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FASTPlaque-Response - A rapid bacteriophage assay for the determination of rifampicin resistance in sputum specimens containing Mycobacterium tuberculosis complex.

FASTPlaqueTB diagnostic kit - A rapid bacteriophage assay for the detection of Mycobacterium tuberculosis complex in clinical specimens.

1/2 Fraser Supplement - For the primary enrichment of Listeria spp from food and environmental samples. For addition to 3/562 Fraser Broth.

17-Beta Estradiol - Indication: Evaluation of ovarian functions. Quantitative determination of 17-ß Estradiol in human serum or plasma. Reaction: 120/30 min, 450nm, 37°C/RT.

Aeromonas Agar - Aeromonas Agar is a highly selective medium for the isolation of Aeromonas spp. from food, clinical and environmental samples. Based on the selective agents brilliant green and irgasan, this medium will not inhibit those strains of Aeromonas sensitive to ampicillin used in other media.

AFP Mab - Quantitative determination of alpha-foetoprotein (AFP) in serum, plasma and amniotic fluid. Reaction: 60/30/15 min, 450-620nm, RT.

Agar No. 1 Bacteriological - A high clarity agar with good gelling properties and a low concentration of metal ions. This agar is suitable for all bacteriological purposes including sensitivity testing and pour plate techniques. A firm gel is obtained at working concentrations of 1.0 to 1.5%. No significant precipitation is observed on reheating or prolonged holding at 65°C.

Agar No. 2 Bacteriological - A bacteriological agar which gives a firm gel at working concentrations of 1.0 to 1.5% and which is reasonably clear. This agar is recommended for all culture media except sensitivity testing media and those where absolute clarity is advantageous.

Amies with Charcoal - Amies introduced his modification of Stuarts Transport Medium to overcome a number of problems. Stuarts Transport Medium suffered from overgrowth by coliforms that were capable of utilising sodium glycerophosphate. Amies replaced the problem component with an inorganic phosphate buffer system. Calcium and magnesium salts are added to control the permeability of the bacterial cell wall and thus prolong their survival. The addition of charcoal to the medium extended the survival time of Neisseria gonorrhoeae from 24 to 72 hours.

Amies without Charcoal - This medium is as 3/404 without the charcoal. It is used when microscopic examination of a film is an important part of the procedure and the charcoal may interfere with interpretation.

Anti A,B - Monoclonal Anti-A,B blood grouping reagent for use in slide and tube tests.

Anti A1 (Lectin) - Anti-A1 Lectin used to differentiate A₁ human red cells from A₂ red cells. For use in slide and tube tests. Biotec Anti-A1 Lectin is an extract from seeds of Dolichos biflorus in a buffered medium.

Anti H (Lectin) - Anti-H Lectin is used to demonstrate the presence of H precursor on human red cells and can be used in ABH secretor status determination. For use in tube test. Biotec anti-H Lectin is an extract from seeds of Ulex europaeus in a buffered medium.

Anti-A - Monoclonal Anti-A blood grouping reagent for use in slide and tube tests.

Anti-A - Monoclonal reagent for use in slide and tube tests.

Anti-A CErytec - The CErytec brand is the new CE Marked line of monoclonal products specially manufactured by Biotec and compliant with the requirements of the European directive 98/79/EC. Products include ABO, Anti-D and Rh/Hr reagents. In developing this new high quality range, Biotec has responded to increasing demand from both within the European Community and from other countries wishing to ensure the quality of reagents used in their laboratories.

Anti-A,B - Monoclonal Anti-A,B blood grouping reagent for use in slide and tube tests.

Anti-A,B CErytec - The CErytec brand is the new CE Marked line of monoclonal products specially manufactured by Biotec and compliant with the requirements of the European directive 98/79/EC. Products include ABO, Anti-D and Rh/Hr reagents. Please note this product is not currently in stock, but will be avialable in the near future In developing this new high quality range, Biotec has responded to increasing demand from both within the European Community and from other countries wishing to ensure the quality of reagents used in their laboratories.

Anti-B - Monoclonal Anti-B blood grouping reagent for use in slide and tube tests.

Anti-B CErytec - The CErytec brand is the new CE Marked line of monoclonal products specially manufactured by Biotec and compliant with the requirements of the European directive 98/79/EC. Products include ABO, Anti-D and Rh/Hr reagents. In developing this new high quality range, Biotec has responded to increasing demand from both within the European Community and from other countries wishing to ensure the quality of reagents used in their laboratories.

Anti-c - Monoclonal Anti-c blood grouping reagent for use in slide, tube and microplate tests.

Anti-C - Monoclonal Anti-C blood grouping reagent for use in slide, tube and microplate tests.

Anti-c - Monoclonal Anti-c blood grouping reagent for use in slide, tube and microplate tests.

Anti-C - Monoclonal Anti-C blood grouping reagent for use in slide, tube and microplate tests.

Anti-c CErytec - The CErytec brand is the new CE Marked line of monoclonal products specially manufactured by Biotec and compliant with the requirements of the European directive 98/79/EC. Products include ABO, Anti-D and Rh/Hr reagents. In developing this new high quality range, Biotec has responded to increasing demand from both within the European Community and from other countries wishing to ensure the quality of reagents used in their laboratories.

Anti-C CErytec - The CErytec brand is the new CE Marked line of monoclonal products specially manufactured by Biotec and compliant with the requirements of the European directive 98/79/EC. Products include ABO, Anti-D and Rh/Hr reagents. In developing this new high quality range, Biotec has responded to increasing demand from both within the European Community and from other countries wishing to ensure the quality of reagents used in their laboratories.

Anti-CDE - Anti-CDE Monoclonal reagent is a human IgG/IgM blood grouping reagents used to confirm the absence of the C, D and E antigens when tested with the slide, tube, microplate and indirect antiglobulin techniques.

Anti-D (IgG & IgM) - Monoclonal Anti-D (IgG & IgM) blood grouping reagent for use in slide and tube tests. Also for use in weak D (D^u) detection.

Anti-D IgG/IgM CErytec - The CErytec brand is the new CE Marked line of monoclonal products specially manufactured by Biotec and compliant with the requirements of the European directive 98/79/EC. Products include ABO, Anti-D and Rh/Hr reagents. In developing this new high quality range, Biotec has responded to increasing demand from both within the European Community and from other countries wishing to ensure the quality of reagents used in their laboratories. Monoclonal Anti-D (IgG & IgM) blood grouping reagent for use in slide and tube tests. Also for use in weak D (D^u) detection.

Anti-D IgM - Anti-D IgM Monoclonal blood grouping reagent for use in slide and tube tests.

Anti-D IgM CErytec - The CErytec brand is the new CE Marked line of monoclonal products specially manufactured by Biotec and compliant with the requirements of the European directive 98/79/EC. Products include ABO, Anti-D and Rh/Hr reagents. In developing this new high quality range, Biotec has responded to increasing demand from both within the European Community and from other countries wishing to ensure the quality of reagents used in their laboratories. Anti-D IgM Monoclonal blood grouping reagent for use in slide and tube tests.

Anti-e - Monoclonal Anti-e blood grouping reagent for use in slide, tube and microplate tests.

Anti-E - Monoclonal Anti-E blood grouping reagent for use in slide, tube and microplate tests.

Anti-E CErytec - The CErytec brand is the new CE Marked line of monoclonal products specially manufactured by Biotec and compliant with the requirements of the European directive 98/79/EC. Products include ABO, Anti-D and Rh/Hr reagents. In developing this new high quality range, Biotec has responded to increasing demand from both within the European Community and from other countries wishing to ensure the quality of reagents used in their laboratories.

Anti-e CErytec - The CErytec brand is the new CE Marked line of monoclonal products specially manufactured by Biotec and compliant with the requirements of the European directive 98/79/EC. Products include ABO, Anti-D and Rh/Hr reagents. In developing this new high quality range, Biotec has responded to increasing demand from both within the European Community and from other countries wishing to ensure the quality of reagents used in their laboratories.

Anti-H (Lectin) - Anti-H Lectin is used to demonstrate the presence of H precursor on human red cells and can be used in ABH secretor status determination. For use in tube test. Biotec anti-H Lectin is an extract from seeds of Ulex europaeus in a buffered medium.

Anti-Human Globulin (Coombs) Green - Polyspecific reagent for detection of IgG and complement binding blood group antibodies, by the direct (DAT) and indirect (IAT) antiglobulin tests. Contains anti-human IgG and anti-human C3d.

Anti-N (Lectin) - Anti-N Lectin reagent is used to determine the presence of the N antigen on human red cells. For use in tube test. Biotec Anti-N Lectin reagent is an extract from leaves of Vicia unijuga in a buffered medium.

Anti-Syphilis IgG/IgM/IgA - Qualitative determination of IgG, IgM and IgA antibodies to Treponema pallidum Reaction: 30/30 min. 450 and 620-690nm, 37ºC/RT.

ASO Latex test kit - A latex slide agglutination test for the qualitative and semi-quantitative detection of Anti Streptolysin O (ASO) in human serum. Streptolysin O is produced by growing strains of Group A haemolytic streptococci (and by most strains of groups C and G). Since this toxin is antigenic, patients with these streptococcal infections form specific antibodies. High and rising titres of ASO may therefore assist in the diagnosis of acute streptococcal infections and their sequelae, such as Glomerulonephritis or rheumatic fever. The test kit includes the following: ASO latex reagent, positive and negative control, test card, pipette stirrers and instructions for use. Results in 3 minutes.

Bacillus Cereus (P.R.E.P.) Medium - Introduced by Mossel and his co-workers in 1967 for the enumeration of Bacillus cereus in foods, this formula was shown to be the most effective for this purpose by Inal in 1972. Two reactions on this medium differentiate B. cereus from other members of the Bacillus group, these are mannitol fermentation and lecithinase production. Mannitol fermentation on this medium produces a yellow colour, B. cereus is mannitol negative and produces red colonies. The lecithinase production of B. cereus is indicated by a white precipitate around the colonies. Polymixin is added to suppress coliforms but some Proteus spp. and Gram positive cocci may grow through. Image: Bacillus cereus on Bacillus Cereus Medium.

Bacteriological Peptone - An economical source of nutrients provided by a balanced mixture of meat peptones and tryptone. The growth requirements of most non-fastidious organisms will be fulfilled by the range of amino acids, peptides and proteoses in this mixture.

Baird Parker Medium Base - Baird-Parker introduced this complex medium in 1962 to overcome the problems of recovering damaged Staphylococcus aureus from foodstuffs. The medium is highly selective due to potassium tellurite and lithium chloride. The tellurite inhibits most coliforms and is also reduced by S. aureus to telluride giving typical black colonies. Glycine and sodium pyruvate are both utilised by staphylococci as growth factors, pyruvate also neutralises toxic peroxides which may be formed in the medium. Sulphamethazine may be added to inhibit Proteus spp. Two reactions typical of S. aureus can be detected by the egg yolk. (1) lecithinase production - an opaque zone round the colony; (2) lipase production - a zone of clearing outside the opaque zone. Colonies suspected of being S. aureus should be confirmed by the coagulase test or by a latex agglutination kit. Image: S. aureus on Baird Parker Medium Base.

Beef Extract (Dehydrated) - This complements the nutritive properties of peptones in culture media and is often used as an added enrichment. Beef extract can be used as a direct replacement for meat peptones and, as it contains no carbohydrates, can be used as a component of media for fermentation studies.

Bismuth Sulphate Agar Base A - A modification of Wilson and Blairs original medium for the isolation of Salmonella typhi and other salmonellae from clinical samples, sewage and other materials. The presence of bismuth sulphite and brilliant green make this medium highly selective. As the medium contains neither lactose nor sucrose it can be used to detect lactose and sucrose fermenting salmonellae. To be used in conjunction with Bismuth Sulphate Agar Base B (3/412B)

Bismuth Sulphate Agar Base B - A modification of Wilson and Blairs original medium for the isolation of Salmonella typhi and other salmonellae from clinical samples, sewage and other materials. The presence of bismuth sulphite and brilliant green make this medium highly selective. As the medium contains neither lactose nor sucrose it can be used to detect lactose and sucrose fermenting salmonellae. To be used in conjunction with Bismuth Sulphate Agar Base A (3/412A)

Blood Agar Base - An inexpensive general purpose agar base which, with the addition of 5% sterile blood, can be used to cultivate a wide range of micro organisms of clinical significance. Typical haemolysis patterns are obtained with this medium.

Blood Agar Base No.2 - A very rich agar base which, with the addition of blood, is capable of growing delicate clinical pathogens. The medium gives colonial appearances, haemolysis patterns and pigment production of diagnostic value. When the blood is ‘chocolated’ the medium gives good recovery of Haemophilus spp. The medium can be made selective for various groups by the addition of appropriate antibiotic mixtures e.g.: Streptococci - Colistin/Oxolinic acid (3/1013) Clostridium perfringens - Neomycin (3/1015, 3/1016) Staphylococci/streptococci - Colistin/Nalidixic acid (3/1012)

Bovine Albumin 22% - To be used as an agglutination enhancing agent in blood group serology. Blood group antibodies of the IgG type are unable to agglutinate red cells directly. The presence of a high molecular weight protein such as bovine albumin helps to overcome this problem.

Bovine Albumin 30% - To be used as an agglutination enhancing agent in blood group serology. Blood group antibodies of the IgG type are unable to agglutinate red cells directly. The presence of a high molecular weight protein such as bovine albumin helps to overcome this problem.

Brain Heart Infusion Agar - A general purpose nutritious agar base. This medium was first used for the isolation of dental pathogens. The mixture of brain and heart infusions is particularly useful in the isolation of Actinomyces israeli and Histoplasma capsulatum. With the addition of 7% defibrinated blood the medium will support the growth of a wide range of fastidious organisms, the phosphate buffer will help neutralise the acids produced from the utilisation of glucose and thus maintain viability. The medium is not recommended for the determination of haemolytic reactions because of the glucose content. The use of porcine material in this product ensures there are no Specified Risk Materials (SRMs) with respect to Transmissible Spongiform Encephalopathies (TSEs).

Brain Heart Infusion Broth - A rich isotonic infusion medium with tryptose (a mixture of meat and milk peptones) providing a wide range of substrates. A low concentration of glucose is used to stimulate early growth. The medium is lightly buffered to prevent the early death of some species due to acid production. Organisms which produce significant amount of acid may well overwhelm the buffering system and auto-sterilise. The medium is suitable for use as a blood culture medium or as an enrichment broth for fastidious organisms. The use of porcine material in this product ensures there are no Specified Risk Materials (SRMs) with respect to Transmissible Spongiform Encephalopathies (TSEs).

Brilliant Green Agar - First introduced by Kristensen et. al. in 1925 as a selective medium for the isolation of salmonellae (except Salmonella typhi). The medium was modified by the Netherlands Institute for Public Health, Utrecht. The modification was to increase the selectivity of the medium by increasing the dye concentration. This formulation is quoted by the International Standards Organisation, standard European Community Methods, the American Public Health Association and the Association of Official Analytical Chemists. The medium is suitable for subcultures from selective enrichment media. However because this medium is highly selective, small numbers of salmonellae may be missed. This medium is definitely not recommended for S. typhi and Shigella spp. Less inhibitory media such as X.L.D. (3/192) and Hektoen Enteric Agar (3/136) will be useful in detecting salmonellae and shigellae inhibited by Brilliant Green Agar. Image: Salmonella sp. on Brilliant Green Agar.

Brilliant Green Bile 2% Broth - A modification of MacConkeys medium, formulated in 1926 by Dunham and Schoenlein, for the recovery of coliform bacteria in foodstuffs and water. The brilliant green and bile inhibit most Gram positive organisms thus overcoming the problem of some Clostridium spp. fermenting lactose and giving false positive results.

Bromocresol Purple Lactose Agar - A non selective differential medium for the isolation and enumeration of Enterobacteriaceae from urine, water and food products. Lactose fermenting organisms produce yellow colonies, non-lactose fermenters produce purple colonies.

Brucella Abortus Antigen - Febrile Antigen for identification and quantification of serum antibodies specific to Brucella abortus infections. This reagent can be used in either slide titration or tube tests.

Brucella Melitensis Antigen - Febrile Antigen for identification and quantification of serum antibodies specific to Brucella melitensis infections. This reagent can be used in either slide titration or tube tests.

Buffered Listeria Broth - A medium for the selective enrichment of food and environmental samples for Listeria spp, 3/556 is a buffered version of the ‘FDA’ Listeria Enrichment Broth (3/462). The extra buffering capacity maintains the pH of the enrichment culture during incubation, ensuring optimum conditions for the recovery of Listeria spp.

Buffered Peptone Water - A pre-enrichment medium designed to help sublethally damaged salmonellae recover before introducing them into a selective medium. This nutrient medium is free from inhibitors and is well buffered to maintain the pH at 7.2 for the incubation period. Sublethal injury to salmonellae occurs in many food processes and this pre-enrichment step greatly increases recovery of these organisms.

C.C.C.F. - Cefotetan, Cycloheximide, Colistin, Fosfomycin, for the isolation of Listeria monocytogenes from environmental, clinical and food samples. For addition to 3/464 Listeria Medium. Acriflavine, the other selective agent used in the Oxford formulation, is a component part of 3/464.

C.F.C. - Cephaloridine, Fucidin, Cetrimide for the selective isolation of Pseudomonas spp. When added to 3/166 Pseudomonas Agar, to prepare C.F.C. medium this supplement can be used to select pseudomonads from food and environmental samples.

C.I.N. - Cefsulodin, Irgasan, Novobiocin for the isolation of Yersinia spp. from clinical and environmental material. For addition to 3/550 Yersinia C.I.N. Agar Base used in the selective isolation of Y. enterocolitica.

Campylobacter Blood-Free Medium - A blood free medium which will support the growth of most enteric campylobacters. The selective cocktail Cefaperazone-Amphoteracin (3/1112) makes the medium selective for Campylobacter jejuni, Campylobacter coli and Campylobacter laridis (C. lari) when incubated at 37°C. With this product incubation at 42°C is no longer necessary and higher recovery rates have been reported at 37°C than at 42°C. The Cefoperazone-Amphoteracin supplement (3/1112) is superior to the selective cocktails of Skirrow, Butzler and Blazer-Wang all of which contain antibiotics shown to be inhibitory to Campylobacter coli. The colonial mophologies of Campylobacter spp. on this medium are distinctive.

Campylobacter Broth - A selective enrichment broth for the isolation of Campylobacter spp. from food, environmental samples and faeces. The use of a selective enrichment broth enhances the recovery of sub-lethally damaged organisms due to processing of foods, or if small numbers of campylobacters are present in heavily contaminated specimens. This broth has been shown to give appreciably better results than Preston Broth.

CEA Mab - Quantitative determination of human carcinoembryonic antigen (CEA) in serum or plasma. Reaction: 60/30/15 min, 450nm, RT.

Cefoperazone Amphoteracin - For the isolation of Campylobacter spp. from clinical, environmental and food samples. Suitable for use with 3/416 Campylobacter Selective Medium (blood free) or with blood agar media. Incubation at 37°C gives better results than at 42°C and is generally more convenient.

Chloramphenicol - For the selective isolation of yeasts and moulds from food, environmental and clinical specimens. Chloramphenicols broad antibiotic spectrum suppresses most contaminating bacteria allowing the yeasts and moulds to grow. It can be added to such media as 3/128 Sabouraud Dextrose Agar, 3/506 Rose Bengal Chloramphenicol Agar, 3/148 Malt Extract Agar and 3/130 Dermatophyte Test Medium to increase their selectivity whilst not lowering the pH. Reduction of pH will increase the selectivity of a yeast and mould medium but will also inhibit some yeasts as well as having a deleterious effect on the agar gel.

CLED Medium (Single Indicator) - A medium for urine culture first described by Mackey and Sandys in 1960. The absence of electrolytes inhibits the swarming of Proteus spp. Cystine is added for the benefit of those organisms which have a specific cystine requirement. Differentiation of lactose and non-lactose fermenters is achieved using bromothymol blue as a pH indicator. This medium supports the growth of Streptococcus pyogenes and most other fastidious organisms that do not require blood.

CLED Medium Bevis (with Andrades) - Bevis modified Sandys’ and Mackeys original medium by introducing a double indicator to improve the differentiation of lactose and non-lactose fermenting coliforms, staphylococci and streptococci. The swarming of Proteus spp. is inhibited. Biotec C.L.E.D. will grow many of the more demanding streptococci of Lancefield groups A, B, C, G and F. This medium may not grow Pasteurella spp. or halophilic organisms.

Clostridium Perfringens - (Perfringens Agar O.P.S.P) This medium was developed by Handford in 1974 to overcome some of the problems associated with enumerating Clostridium perfingens in foods. The medium is buffered and utilises sodium metabisulphite and liver extract as sources of H2S with ferric ammonium citrate as the indicator. The medium is made selective with the addition of sulphadiazine (3/1109) and oleandomycin/polymixin (3/1110) supplements.

CMV IgG - Qualitative determination of IgG antibodies to CMV (Cytomegalovirus) in human serum or plasma. Reaction: 15/15/5 min, 450nm, RT.

CMV IgM - Qualitative determination of IgM antibodies to CMV (Cytomegalovirus) in human. Reaction: 15/15/10 min, 450nm, RT.

Colistin Nalidixic Acid - For the preparation of Columbia C.N.A. medium. A medium selective for Gram positive cocci is obtained when this antibiotic mixture is added to 3/426 Columbia Agar.

Colistin/Oxolinic Acid - For the selective isolation of streptococci from clinical material. When added to 3/426 Columbia Agar or 3/104 Blood Agar Base No. 2, 3/1013 renders the medium selective for streptococci. Alteration in haemolysis patterns may occur when azide or crystal violet are employed as selective agents but this does not occur with 3/1013.

Columbia Agar Base - A general purpose nutritious agar base formulated by Ellner et al. When further enriched by the addition of sterile blood, Columbia Agar can be used for the isolation of most clinically significant pathogens. The blood can be ‘chocolated’ if required. The medium can be made selective for various groups by the addition of appropriate antibiotic mixtures e.g.: Streptococci colistin/oxolinic acid 3/1013 Clostridium perfringens neomycin 3/1015 or 3/1016 Staphylococci/streptococci colistin/nalidixic acid 3/1012

Cooked Meat Medium - This is a complete version of Robertsons Cooked Meat Broth, which was designed to grown all anaerobes found in battlefield wounds during the First World War. The medium is based on Cooked Meat Granules and Nutrient Broth No. 2 (3/160).

Cortisol - Indication: Adrenocortical insufficiency (Addison´s disease), Cushing´s syndrome, Growth disturbance in children. Quantitative determination of Cortisol in human serum or plasma. Reaction: 60/15 min, 450nm, 37°C/RT.

CRP Latex test kit - A rapid latex slide agglutination test for the qualitative and semi-quantitative estimation of C-reactive protein (CRP) in human serum. The Biotec CRP test kit will detect CRP levels of between 5-10mg/l. The test kit includes the following: CRP latex reagent, positive and negative control, test card, pipette stirrers and instructions for use. Results in 3 minutes.

Cycloserine Cefoxitin - For the isolation of Clostridium difficile from clinical materials. Suitable for use with 3/442 Fastidious Anaerobe Agar.

DCA (Hynes) - This modification of Leifsons D.C.A. medium was introduced in 1942. The medium was designed to be more inhibitory to commensal flora whilst allowing for adequate growth of Salmonella spp. and Shigella spp. The citrate and desoxycholate levels are significantly increased. To keep the desoxycholate in solution the pH also had to be increased. The medium still uses lactose fermentation and hydrogen sulphide production as differential indicators.

DCA (Leifsons) - This is Leifsons original formulation of this selective medium for the isolation of Salmonella spp. and Shigella spp. from faeces and environmental samples. It has approximately half the quantity of inhibitors used in the Hynes modification. The medium uses sodium citrate and sodium desoxycholate as inhibitors. Sodium thiosulphate is the substrate for the enzyme thiosulphate reductase being broken down to form sulphite and hydrogen sulphide. The hydrogen sulphide reacts with the ferric ions to produce a black precipitate of ferrous sulphide. This gives a typical black centre to the colonies of most species of Salmonella.

DCLS Agar - A modification of Leifsons D.C.A. medium which incorporates sucrose as an additional fermentable substrate to differentiate lactose negative sucrose positive coliforms from Salmonella spp. This medium is unsuitable for the isolation of Yersinia spp. which are sucrose positive.

Dermatophyte Test Medium - A modification of the formulation of Taplin, Zaias, Rebell and Blank for the detection of dermatophytic fungi. This medium helps in the differentiation between saprophytic and environmental fungi.

Dextrose Tryptone Agar - A medium for the enumeration of thermophilic spore bearers in foods. The medium was designed to detect the thermophilic bacteria which cause ‘flat sour’ spoilage of canned foods. The medium also detects the ‘flat sour’ organism Bacillus stearothermophilus in sugar and other sweetening agents used in the preparation of frozen dairy foods, cereals and other food products.

DHEA-S - Indication: Adrenal hyperplasia, differential diagnosis of hirsutism. Quantitative determination of DHEA-S (Dehydroepiandrosterone sulphate) in human serum or plasma. Reaction: 60/15 min, 450nm, 37°C/RT.

Diagnostic Semi-Solid Salmonella Agar - Diassalm, as developed by Van Netten et. al. (1991), is a semi-solid differential medium for the isolation of Salmonella spp. from food and water. It is an improved modification of MSRV (De Smedt and Bolderdijk, 1988) and SR (Perales and Audicana, 1989) with regard to the composition of the basal medium, selective system and the introduction of a differential system. The original basal medium was a commercially available sulphide motility-indole medium (SIM, BBL, Blazevic, 1968). Biotec have substituted their raw materials into Blazevics formula to create a richer base for Diassalm. Selectivity is achieved by the use of malachite green oxalate, magnesium chloride and novobiocin. The diagnostic properties of Diassalm are based on the use of two indicator systems; saccharose combined with bromocresol purple; and ferro-iron in combination with thiosulphate. The efficiency of Diassalm is due to the ability of salmonellae to move through the highly selective motility medium in a petri dish, whilst the double diagnostic system allows visualisation of motile and non-motile suspected salmonellae due to blacking zones against the turquoise background. Diassalm can be seeded after pre-enrichment or after 8 hour enrichment in selective broth (De Smedt and Bolderdijk, 1987).

Direct Monoclonal Pregnancy 200 i.u. - A direct latex slide agglutination test, based on use of monoclonal antibody coated latex particles, for the qualitative determination of hCG in urine. Sensitivity of 200 IU/L. The test kit includes the following: hCG latex reagent, positive and negative control, test card, pipette stirrers and instructions for use. Results in 2 minutes.

DNase Agar - DNase agar provides a convenient means of identifying potentially pathogenic staphylococci, based on the ability of coagulase-positive species to split DNA. DNases produced by the organisms hydrolyse the DNA molecule to a mixture of smaller mono and poly nucleotides. DiSalvo observed perfect correlation between coagulase activity and DNase production using Staphylococcus aureus strains from clinical specimens. Other publications have also reported a close correlation.

E.E.Broth - E.E. Broth is recommended as an enrichment medium when examining food and feedstuffs for Enterobacteriaceae. It is a modification of Brilliant Green Bile 2% Broth (3/112) with an improved buffering capacity to encourage early growth and prevent auto-sterilisation. E.E. Broth uses glucose instead of lactose to make the medium a test for all enterobacteria including non-lactose fermenting organisms.

Egg Yolk Emulsion - A sterile emulsion of egg yolks for use in bacteriological culture media. It may be added directly to nutrient media for the identification of Clostridium, Bacillus, and Staphylococcus species by their lipase and/or lecithinase activity.

Egg Yolk Tellurite - A sterile emulsion of egg yolk and potassium tellurite for use as a selective and differential agent in 3/100 Baird-Parker Medium Base. The complete medium is selective for S. aureus, and the addition of egg yolk tellurite aids differentiation of this organism from others capable of growing on the agar.

Endo Agar - This medium was developed in 1914 for the isolation of Salmonella typhi; other media have since proved superior for this purpose, but Endo agar has a role as a coliform medium. It is recommended by the American Public Health Association as a standard medium for the enumeration of coliforms in water and dairy products. In this medium acetaldehyde is produced by coliforms and then fixed by the sulphite to produce a metallic sheen with the basic fuchsin dye. Most enteric Gram negative organisms will grow well, whilst Gram positive organisms are mostly inhibited.

Eosin Methylene Blue Agar (Levine) - This medium was introduced in 1916 by Holt-Harris and Teague to differentiate Escherichia spp. and Aerobacter spp. It was modified by Levine in 1918 who removed sucrose from the formula and increased the lactose content. The distinctive metallic sheen produced by Escherichia coli on this medium is due to acid production resulting in an amide bonding between the eosin and methylene blue. Other coliforms do not produce enough acid to cause this reaction. Eosin inhibits most Gram positive organisms. The prepared medium is sensitive to light.

Fastidious Anaerobe Agar - A primary isolation medium capable of growing most clinically significant anaerobes. Comparisons have shown this medium to be superior to other formulations as a primary isolation medium for fastidious organisms. The peptones included have been chosen for maximum growth stimulation. Starch and sodium bicarbonate act as de-toxification agents whilst haemin encourages pigment production in Porphryromonas melaninogenicus. Specific growth promoting agents are cysteine for Fusobacterium necrophorum, Propionibacterium acnes and Bacteroides fragilis, arginine for Eubacterium spp. soluble pyrophosphate for Porphryromonas gingivalis and Porphyromonas assacchrolyticus. Pyruvate helps neutralise hydrogen peroxide and is also utilised by Veillonella spp. as an energy source. Vitamin K and sodium succinate provide essential growth factors for some anaerobes as does the 0.1% glucose. The low level of glucose prevents the production of high levels of acids and alcohols which would inhibit colonial development. Image: Mixed anaerobes on Fastidious Anaerobe Agar.

Fastidious Anaerobe Broth - Fastidious Anaerobe Broth was developed in conjunction with the microbiology department of a University of Manchester teaching hospital. The medium was designed to give optimum growth of fastidious anaerobes and has found applications as a blood culture medium and an enrichment broth for the isolation of anaerobes. The medium is very rich in nutrients from the specially selected peptone mixture. Vitamin K, haemin and L-cysteine are all growth factors required by some anaerobes. L-cysteine and sodium thioglycollate reduce the Eh (redox potential) of the medium and the agar content inhibits absorption of oxygen and convection currents. Resazurin is a redox indicator. Several published evaluations show Fastidious Anaerobe Broth to be the liquid medium of choice for fastidious anaerobes.

Febrile antigen kit comprising 8 specified antigens - Kit containing 8 Salmonella O and H febrile antigens (2/012-2/028).

Febrile antigen kit comprising 8 specified antigens with positive and negative controls - Kit containing 8 Salmonella O and H febrile antigens (2/012-2/028) and one each of the febrile positive and negative controls.

Febrile negative control sera - Negative control sera for use with the Biotec febrile antigen reagents.

Febrile positive control sera - Positive control sera for use with the Biotec febrile antigen reagents.

Ferritin - Enzyme-Immunoassay for the quantitative determination of Ferritin in serum and plasma. Reaction: 30/10 min. 450/405nm RT/37°C.

Fluid Thioglycollate Medium USP - A medium for sterility tests, prepared according to the specification of the United States Pharmacopeia. Aerobic and anaerobic organisms grow well in this medium even from small inocula. In appropriate tubes or bottles the thioglycollate ensures adequate anaerobic conditions. The low level of agar reduces oxygen diffusion into the medium. The thioglycollate will also serve to inactivate any mercurial compounds used as preservatives.

Fraser Broth - Developed as a modification of UVM II, Fraser Broth is a secondary enrichment broth for the isolation of Listeria spp. and is similar to Palcam Broth in that it contains aesculin to indicate the presence of a potential Listeria isolate. It also contains lithium chloride (as does Palcam Broth) in an attempt to suppress the growth of enterococci in the medium. Fraser Broth may also be used as a primary enrichment medium by incorporating ½ strength supplement into the broth base (3/1164).

Fraser Supplement - For the secondary enrichment of Listeria spp from food and environmental samples. For addition to 3/562 Fraser Broth.

FSH - Indication: Gonadal insufficiency, hypothalamic pituitary insufficiency. Quantitative determination of FSH (follicle stimulating hormone) in human serum or plasma. Reaction: 60/10 min, 450nm, RT.

FT3 - Indication: Hyper- or Hypo-Thyroidism. Quantitative determination of FT3 (Free Triiodothyronine) in human serum. Reaction: 60/15 min, 450nm and 620/630 nm, RT.

FT4 - Indication: Hyper- or Hypo-Thyroidism. Quantitative determination of FT4 (Free Thyroxine) in human serum. Reaction: 60/15 min, 450nm and 620/630 nm, RT.

GC Agar Base - A nutritious agar base described by Thayer and Martin for the isolation of Neisseria gonorrhoeae. The right peptone mixture is enhanced by the use of corn starch to absorb toxic metabolites and a buffering system is used to maintain neutral pH. The medium is made selective by the use of various antibiotic cocktails. Thayer and Martin originally recommended the use of vancomycin, colistin and nystatin (V.C.N.) but the addition of trimethoprim (3/1068 V.C.N.T.) is useful in preventing the swarming of Proteus spp.. More recently the emergence of vancomycin sensitive gonococci has made the New York City selective agent (lincomycin, colistin, amphoteracin, trimethoprim, 3/1070 L.C.A.T.) the combination of choice. Enrichment of the base is usually by the addition of lysed blood. Alternatively chocolated blood or haemoglobin powder and Thayer and Martins mixture of vitamins, amino acids and coenzymes can be used. The supplement 3/1069 (L.C.A.T. for Modified New York Medium) can be added as this is without Amphotericin and this permits the growth of yeasts. The growth supplement 3/1271 (GC Growth Supplement) can be added to aid in the isolation of Neisseria spp.

GC Growth Supplement - To improve the isolation of Neisseria spp from selective media. For addition to 3/314 GC Agar Base.

HAV Ab - Qualitative determination of antibodies to Hepatitis A Virus in human serum or plasma. Reaction: 120/20 min, 450nm and 620/630nm, 37°C/RT.

HAV IgM - Qualitative determination of IgM antibodies to Hepatitis A Virus in human serum or plasma. Reaction: 60/60/20 min, 450nm and 620/630nm, 37°C/RT.

HBcAb Screening - Semiquantitative determination of antibodies to Hepatitis B core Antigen in human serum or plasma. Reaction: 120/20 min 450nm and 620/630nm, 37°C/RT.

HBeAg - Semiquantitative determination of Hepatitis B envelope "e" Antigen in human serum or plasma. Reaction: 120/60/20 min, 450nm and 620/630nm, 37°C/RT.

HBsAb - Quantitative and qualitative determination of antibodies to Hepatitis B Virus in human serum or plasma. Reaction: 120/60/20 min, 450nm and 620/630nm, 37°C/RT.

HBsAg (3rd Generation) - Qualitative determination of Hepatitis B Surface Antigen (HBsAg) in human serum or plasma. Reaction: 60/15 min, 450nm and 630nm, 37°C.

HBsAg rapid device (serum/plasma) - A rapid chromatographic immunoassay for the qualitative detection of Hepatitis B Surface Antigen in serum or plasma. The test utilises a combination of monoclonal and polyclonal antibodies to selectively detect elevated levels of HBsAg.

hCG - Indication: Early detection of pregnancy, chorion epithelioma and embryonic cell carcinoma. Quantitative determination of ß-hCG (human chorionic gonadotropin ß-chain) in human serum or plasma. Reaction: 30/30/15 min, 450nm, RT.

hCG Rapid Strip in pouch - A rapid chromatographic immunoassay for the qualitative detection of human chorionic gonadotrophin (hCG) in urine, to aid in the early detection of pregnancy. The test utilises a combination of antibodies including monoclonal hCG antibody to selectively detect elevated levels of hCG in urine, at the sensitivity of 25 mIU/ml.

hCG Rapid Strips in tube - A rapid chromatographic immunoassay for the qualitative detection of human chorionic gonadotrophin (hCG) in urine, to aid in the early detection of pregnancy. The test utilises a combination of antibodies including monoclonal hCG antibody to selectively detect elevated levels of hCG in urine, at the sensitivity of 25 mIU/ml.

HCV Ab (3rd Generation) - Qualitative determination of antibodies to Hepatitis C Virus in human serum or plasma. Reaction: 30/30/10 min, 450nm and 620/630nm, 37°C.

HCV rapid device (serum/plasma) - A rapid chromatographic immunoassay for the qualitative detection of antibody to Hepatitis C Virus in serum or plasma. The test utilises a combination of protein A coated particles and recombinant HCV proteins to selectively detect antibody to HCV. The recombinant HCV proteins used in the device are encoded by the genes for both structural (nucleocapsid) and non-structural proteins.

Hektoen Enteric Agar - A medium developed at the Hektoen Institute in Chicago for the enhanced recovery of Shigellae from clinical specimens. This medium has high levels of peptones and sugar, which counteract some of the toxic effects of bile salts used to make the medium selective. This allows the shigellae to grow as well as the salmonellae. Salicin is fermented by many coliforms including those that do not ferment lactose and sucrose. The medium employs a double indicator system similar to that used in C.L.E.D. Medium (Bevis with Andrades, 3/118) and an H2S indicator system similar to that used in XLD (3/192). Although intended primarily for clinical use, this medium is quoted in B.S. 4285 as suitable for the examination of dairy products for salmonellae. Image: Mixed organisms on Hektoen Enteric Agar.

Helicobacter Pylori Agar Base - A selective medium for the isolation of Helicobacter pylori, the causative agent of chronic gastritis. This Campylobacter-like organism was described in 1983 colonising the gastric mucosa, a site previously thought to be sterile due to low pH. The high level of urease production by this organism appears to be the major pathogenicity factor enabling it to withstand the strongly acidic environment. Helicobacter pylori Medium is a modification of CCDA Medium for the isolation of Campylobacter spp. Formulated by Bolton et. al. at Preston Public Health Laboratory, it incorporates a rich agar base supplemented with horse serum to promote optimum growth, and Vancomycin, Cefsulodin, and Amphoteracin as selective agents.

HEV IgM - Semi-quantitative determination of antibodies to Hepatitis E Virus in human serum or plasma. Reaction: 60/60/20 min, 450nm and 620/630nm, 37°C/RT.

hGH - Indication: Hypothalamic pituitary retarded excessive growth, hypothalamic pituitary dwarfism or gigantism quantitative determination of hGH (human growth hormone) in human serum. Reaction: 60/15 min, 450 nm, RT.

HIV 1 & 2 rapid device (serum/plasma) - A rapid chromatographic immunoassay with a double antigen system for the qualitative detection of antibodies to Human Immunodeficiency Virus (HIV) type-1 and/or type-2 in serum or plasma. The test utilises gold conjugate and multiple recombinant HIV proteins, to selectively detect antibodies to HIV-1 and HIV-2.

HIV 1&2 - Qualitative determination of antibodies to Human Immunodeficiency Virus Type 1 and Type 2, in human serum or plasma. Reaction: 60/30/10 min, 450nm and 620nm, 37°C.

Hoyles Medium Base - A highly selective culture medium for the isolation and differentiation of Corynebacterium diphtheriae types gravis, mitis and intermedius. Hoyles medium gives rapid growth of all types of C. diphtheriae, which results in most specimens giving adequate growth with overnight incubation.

HSV 1 IgG - Qualitative determination of IgG antibodies to HSV Type 1 in human serum. Reaction: 15/15/5 min, 450nm, RT.

HSV 1 IgM - Qualitative determination of IgM antibodies to HSV Type 1 in human serum. Reaction: 15/15/10 min, 450nm, RT.

HSV 1+2 IgG - Qualitative determination of IgG antibodies to Herpes Simplex Virus (HSV) Type 1 & 2 in human serum or plasma. Reaction: 15/15/5 min, 450nm, RT.

HSV 1+2 IgM - Qualitative determination of IgM antibodies to HSV Type 1 & 2 in human serum or plasma. Reaction: 15/15/10 min, 450nm, RT.

HSV 2 IgG - Qualitative determination of IgG antibodies to HSV Type 2 in human serum. Reaction: 15/15/5 min, 450nm, RT.

HSV 2 IgM - Qualitative determination of IgM antibodies to HSV Type 2 in human serum. Reaction: 15/15/10 min, 450nm, RT.

Kanamycin 75 - For the selective isolation of Clostridium spp. and other anaerobes. An alternative to 3/1015. Kanamycin is more inhibitory to anaerobic cocci.

Kanamycin Agar (Streptococcus) - A selective isolation and enumeration medium for enterococci (Lancefield group D streptococci) in food. Sodium azide and kanamycin provide the selective inhibition required whilst aesculin and iron salts form an indicator system for the presumptive identification of enterococci. Incubation at 42*C will increase the mediums selectivity.

Kanamycin Broth - An enrichment and isolation medium for enterococci. The medium can be used with the Most Probable Number ( M.P.N.) technique to enumerate enterococci in food. This broth is identical to Kanamycin Agar (3/454) with the omission of the agar.

Kliglers Iron Agar - A differential medium for the recognition of enteric pathogens by their ability to ferment glucose and/or lactose, and liberate sulphides. Fermentation liberates acid, with or without gas, turning phenol red indicator yellow. Fermentation of glucose only, is followed by reversion in pH on the slope, from initial acidity to final alkalinity (red colour), but not in the anaerobic conditions of the butt, which remains acid (yellow). Fermentation of lactose as well as glucose, produces acidity in both slope and butt (yellow). Liberation of sulphide results in the formation of iron sulphide (blackening of either slope or butt).

L.C.A.T. for Mod. New York - Lincomycin, Colistin, Amphoteracin, Trimethoprim for the isolation of Neisseria spp. from clinical material. L.C.A.T. is often preferred to 3/1068 V.C.N.T. for the isolation of N. gonorrhoeae because of the emergence of vancomycin sensitive strains. The antifungal agent amphoteracin is more readily soluble and therefore a more active antifungal than nystatin. L.C.A.T. is quoted as the selective agent for New York City G.C. Agar but can readily be substituted for V.C.N. or V.C.N.T. in Thayer Martin G.C. Agar.

L.C.T. for Mod. New York Medium - Lincomycin, Colistin, Trimethoprim. A variant of L.C.A.T. with the amphoteracin omitted to permit the growth of yeasts.

Lactose Broth - A medium for the performance and confirmation of the Presumptive Test for members of the coliform group in water and dairy products, recommended by the U.S.P.

LH - Indication: Gonadal insufficiency, hypothalamic pituitary insufficiency. Quantitative determination of LH (Luteinising hormone, lutropin) in human serum or plasma. Reaction: 60/15 min, 450nm, RT.

Listeria Broth - A medium for the selective enrichment of food and environmental samples for Listeria spp., first described in 1987 by J. Lovett. The medium offers more rapid enrichment than the low temperature enrichment techniques. This medium is now recommended by the Commission of European Communities and the International Dairy Federation for the examination of soft cheeses for Listeria monocytogenes. The medium is incubated at 30°C and utilises acriflavine, nalidixic acid and cycloheximide as selective agents.

Listeria Medium - A selective identification medium for the isolation of Listeria monocytogenes from food and clinical material. Columbia agar is the nutrient base to which selective inhibitors have been added. Lithium chloride is used to inhibit enterococci and acriflavine is used to inhibit some Gram negative and Gram positive species. Further selective agents may be added after autoclaving to increase the selectivity; these are colistin, fosfomycin, cefotetan and cycloheximide. Aesculin is included in the formula as a differential indicator. L. monocytogenes will hydrolyse aesculin to aesculutin which reacts with the iron salt to give a black precipitate around the colonies.

Low Ionic Strength Solution - Biotec LISS is “ready-to-use” solution supplied at the optimal dilution, for use with all recommended techniques without the need for further dilution or addition.

M.L.C.B. Agar - A medium for the selective isolation of Salmonella spp. (with the exception of Salmonella typhi and Salmonella paratyphi A) from food and faeces. Salmonella colonies are recognised by distinctive colonial appearance and H₂S production and like the Bismuth Sulphite Agar of Wilson & Blair, this medium will detect lactose and sucrose fermenting strains. Some problems may occur with H₂S negative strains, e.g. Salmonella pullorum, Salmonella senftenberg, Salmonella sendai and Salmonella berta. This medium should not be used to detect S. typhi or S. paratyphi A, as these organisms are more susceptible to the brilliant green dye.

M.R.S. Agar - This medium was developed for the cultivation and enumeration of Lactobacillus spp. from various sources and is intended as a substitute for Tomato Juice Agar. The medium is suitable for most lactic acid bacteria. When acidified to pH 5.4, M.R.S. Agar can be used to enumerate Lactobacillus bulgaricus in yoghurts. Tween 80, sodium acetate, magnesium and manganese sulphates act as growth stimulants.

MacConkey Agar (Sorbitol) - This is a selective differential medium for the isolation of Escherichia coli 0157:H7, the primary serovar associated with haemorrhagic colitis (HC) and haemolytic uraemic syndrome (HUS). Pathogenicity of the organism is linked to the production of verocytotoxins (VT1 and VT2), but it should be noted that not all strains of 0157:H7 produce verocytotoxins and that strains from other serovars can be toxin producers (e.g. 026, 0111, 0113, 0145). 0157:H7 has been associated epidemiologically with food poisoning outbreaks involving beefburgers and cold cooked meats. The medium is a modification of MacConkey Agar No. 3 (3/144) with the substitution of the fermentable carbohydrate from lactose to sorbitol. 0157:H7 is sorbitol negative and produces translucent colonies whereas most other E. coli strains are sorbitol positive and so produce pink/red colonies.

MacConkey Agar (with salt) - A selective medium for the isolation of bile tolerant organisms from faeces, urine, sewage and foodstuffs. Bile-tolerant Gram positive organisms as well as Gram negative organisms will grow on this medium. This formula is recommended by the W.H.O. and other bodies for the examination of water and milk. Some strains of Proteus spp. will spread on this medium making interpretation difficult, for this reason MacConkey Agar Without Salt (3/140) may be preferred as it is less prone to this phenomenon.

MacConkey Agar (without salt) - A medium first introduced by MacConkey in 1905 for the isolation and differentiation of lactose and non-lactose fermenting enteric bacteria. The medium has since been modified to improve the recovery of staphylococci and enterococci. It is used for culturing a wide range of clinical material and has applications in food, water and dairy bacteriology.

MacConkey Agar No. 3 - A modification recommended by the W.H.O. and the American Public Health Association for the isolation of Enterobacteriaceae from waters and sewage. The medium has been made more selective than MacConkeys original formula by the use of crystal violet as well as bile salts. Gram positive organisms will not grow on this medium.

MacConkey Broth Purple - This medium is used in the detection and enumeration of faecal coliforms at 37°C and Escherichia coli at 44°C. The replacement of neutral red, used in the original formulation, by bromocresol purple makes the colour change, caused by acid producing organisms, easier to read.

Malaria Pan/Pf Rapid Device (whole blood) - A rapid, qualitative, two site sandwich immunoassay, for the detection of P. falciparum specific histidine rich protein-2 (Pf HRP-2) and pan specific pLDH. The test may also be used for differentiation of P. falciparum and other malarial species and for the follow up of anti-malarial therapy.

Malaria Pan/Pv/Pf Rapid Device (whole blood) - A rapid, qualitative, two site sandwich immunoassay for the detection of P. falciparum specific histidine rich protein-2 (Pf HRP-2), P. vivax specific pLDH and pan malaria specific pLDH. The test can be used for the specific detection of P. falciparum and P.vivax malaria, differentiation of other malarial species and for the follow up of anti malarial therapy.

Malaria Pf Rapid Device (whole blood) - A rapid, qualitative, two site sandwich immunoassay for the determination of P. falciparum specific histidine rich protein–2 (Pf HRP-2) in whole blood.

Malaria Pv/Pf Rapid Device (whole blood) - A rapid, qualitative, two site sandwich immunoassay for the detection of P. falciparum specific histidine rich protein-2 (Pf HRP-2) and P. vivax specific pLDH. Also for use for specific detection and differentiation of P. falciparum and P. vivax malaria in areas with high rates of mixed infections.

Malt Extract Agar - An acidic medium which will support the growth of most yeasts and moulds whilst inhibiting most bacteria. It was first described by Thom and Church in 1926 in a study of Aspergillus spp. claiming the high carbohydrate content ensured rapid growth. It should be noted that excess heating of this medium together with its low pH can easily result in hydrolysis of the agar gel producing soft plates.

Malt Extract Broth - A liquid medium of low pH for the growth of yeasts and moulds, typically employed as part of sterility testing protocols for various products. The high carbohydrate content of the medium ensures rapid growth of yeasts and moulds.

Malt Extract Powder - A water soluble extract of malted barley suitable for use in the cultivation of yeasts and moulds. Malt extract has a very high carbohydrate content and consequently is very sensitive to over heating which will cause a darkening of the medium.

Mannitol - D-Mannitol for use in microbiological culture media

Mannitol Salt Agar - A medium for staphylococci which is selective because the high sodium chloride level inhibits most other species with the exception of halophilic vibrios. The majority of Staphylococcus aureus ferment mannitol producing yellow colonies, occasional strains of coagulase negative staphylococci may also ferment mannitol. It is necessary to confirm the identity of presumptive S. aureus colonies by other means e.g. coagulase, protein A, DNase, thermonuclease or latex agglutination. Image: S. aureus on Mannitol Salt Agar.

Maximal Recovery Diluent - An osmotically controlled solution which is an alternative to and a replacement for ¼ strength Ringers Solution. The presence of a low level of peptone lessens the physiological shock normally experienced by bacterial cells when they are introduced to a diluent such as Ringers Solution. The level of peptone is such that multiplication of the organisms is not possible in the time in which the sample will be present in the diluent (1-2 hours). This formula is recommended by ISO 6887: BS5763.

Membrane Lauryl Sulphate Broth - This medium superseded Membrane Enriched Teepol Broth when Shell Chemicals withdrew Teepol 610 from sale. Sodium lauryl sulphate was found to be an adequate reproducible substitute and this medium is recommended for the enumeration of organisms in water and sewage.

Metronidazole Nalidixic Acid - For the isolation of Actinomyces spp. from clinical material. Suitable for use with 3/442 Fastidious Anaerobe Agar. The metronidazole will suppress the growth of most other anaerobes.

Milk Plate Count Agar - A medium recommended by the British Standards Institute and the International Organisation for Standardisation for the enumeration of viable bacteria in milk and other dairy products.

Minerals Modified Glutamate Medium - This medium was developed for use with the Most Probable Number (M.P.N.) Technique for the enumeration of coliforms in water supplies. The medium is an improved version of the chemically defined glutamic acid medium described by Gray in 1964. The product is supplied in two parts because it has been shown that separating the sodium glutamate from the base improves its stability.

Modified T.S.B. (for E. Coli) - Modified Tryptone Soy Broth has emerged as the medium of choice for the enrichment of Escherichia coli O157:H7 in red meats. As concern regarding this organism has grown due to the severity of the disease syndromes caused and the increase in foodborne infection, so too has the need to optimise methods for its efficient isolation. Symptoms start with severe stomach cramps and watery, bloody diarrhoea. A percentage of infected individuals will develop Haemolytic Uraemic Syndrome (HUS) leading to acute renal failure. In a comparison of 4 different selective broth media, Modified Tryptone Soy Broth was the most productive and selective for the isolation of E. coli O157:H7. Modified Tryptone Soy Broth is made selective for O157:H7 by including bile salts in the dehydrated medium, and the addition of novobiocin supplement (3/1150).

Mueller Hinton Agar - A medium for antimicrobial sensitivity testing by the disc diffusion method. This medium, used in the technique of Bauer and Kirby, has been adopted by the National Committee for Clinical Laboratory Standards (N.C.C.L.S.) in the USA as the definitive method for susceptibility testing. The medium has a very low thymine and thymidine content, making it suitable for trimethoprim and sulphonamide testing, controlled to ensure correct zone sizes with aminoglycoside and tetracyline antibiotics. The medium was originally formulated as a heat labile protein-free medium for the isolation of pathogenic Neisseriaceae.

Mueller Hinton Broth - This medium is the broth version of Mueller Hinton Agar (3/156). It is an antagonist free medium for use in the tube dilution technique for the determination of antibiotic M.I.C. values. The medium is carefully standardised to meet N.C.C.L.S. standards for antimicrobial susceptibility tests on bacteria which grow aerobically.

Mueller Kauffman Tetrathionate - A selective enrichment broth for salmonellae first described by Mueller, in 1923, then modified by Kauffman, in 1935, with the addition of brilliant green and ox bile increasing its selectivity. Organisms which can utilise tetrathionate, such as most salmonellae, flourish. However some salmonellae will be missed in this medium either because they are sensitive to brilliant green or cannot utilise tetrathionate (included in this group is Salmonella typhi). This medium is used in the standard European Community Salmonella Isolation Procedure and in International Standards Organisation (ISO) Methods.

Nalidixic Acid - For the isolation of non-sporing anaerobes from clinical material. Suitable for use with 3/442 Fastidious Anaerobe Agar. When used with other blood agar bases, e.g. 3/426 Columbia Agar, further enrichment of the medium with haemin, menadione and sodium pyruvate is beneficial. The addition of Tween 80, which, enhances the growth of anaerobic cocci, to the medium is required for N.A.T. medium. The Tween 80 may be added before sterilization at a concentration of 0.1%.

Nalidixic Acid Vancomycin - For the isolation of Gram negative anaerobes from clinical material. Suitable for use with 3/442 Fastidious Anaerobe Agar. When used with other blood agar bases, e.g. 3/426 Columbia Agar, further enrichment of the medium with haemin and menadione is beneficial.

Negative Syphilitic control serum - Control reagents for use with Biotec Laboratories VDRL Carbon Antigen.

Neomycin 100 - For the selective isolation of Clostridium spp. When added to egg yolk medium this supplement will allow the growth of clostridia whilst inhibiting other lecithinase producing organisms.

Neomycin 75 - For the isolation of Clostridium spp. and other anaerobes. When added to blood agar the resulting medium will allow the growth of clostridia, most Bacteriodes fragilis strains and some anaerobic cocci.

NOA supplement - An antimicrobial supplement for use with the FASTPlaque-Response test to inhibit the growth of contaminating bacterial and fungal organisms commonly found in respiratory specimens.

Novobiocin - For the isolation of Salmonella using semi-solid technology. For addition to MSRV and 3/433 Diassalm

Novobiocin for M.S.R.V. - For the isolation of Salmonella using semi-solid technology. For addition to MSRV and 3/433 Diassalm.

Nutrient Agar - A general purpose medium for the cultivation of organisms that are not demanding in their nutritional requirements e.g. organisms that can be isolated from air, water, dust etc. Nutrient Agar is suitable for teaching and demonstration purposes. It is isotonic and can be enriched with biological fluids such as sterile blood and egg yolk.

Nutrient Broth E - An inexpensive broth for the growth of nutritionally non demanding organisms. Ideal for teaching purposes.

Nutrient Broth No. 2 - A general purpose broth which can be used for sterility testing for aerobic organisms as recommended by the British Pharmacopoeia. This broth can also be used as the suspending medium for cooked meat granules for the cultivation of anaerobic organisms.

O.G.Y.E. Agar Base - A selective medium for the enumeration of yeasts and moulds in food, introduced by Mossel in 1970. Unlike many selective media for yeasts O.G.Y.E. has a neutral pH and it has been shown to give better recovery rates than those media with a low pH. Oxytetracycline is used to inhibit bacteria, certain high protein foods may reduce the effectiveness of this antibiotic as a selective agent. Rose Bengal Chloramphenicol Agar (3/506) is recommended in these instances.

Oleandomycin Phos. Polymixin - For use with Perfringens agar to prepare O.P.S.P. for the selective isolation of Clostridium perfringens from foodstuffs.

Oxytetracycline - For O.G.Y.E. medium. For use with 3/488 Oxytetracycline Glucose Yeast Extract Agar for the enumeration of yeasts and moulds from foodstuffs. Highly proteinaceous foods and incubation above 30°C will inactivate oxytetracycline.

P.A.C. - For the enrichment and isolation of Listeria spp from food and environmental samples. For the addition to 3/161 Palcam Agar and Palcam broth.

Palcam Agar Base - Palcam Agar was developed by Van Netten et al in 1989 as an improved selective differential medium for the isolation of Listeria monocytogenes from food, clinical and environmental specimens. Improved selectivity is achieved by the combination of antibiotic supplements and microaerobic incubation, whilst the double indicator system of aesculin hydrolysis and mannitol fermentation aids differentiation of Listeria spp. from enterococci and staphylococci which can be confused with Listeria spp. on other types of culture media. Image: L. monocytogenes on Palcam Agar

Peptone Water - A general purpose growth medium that can be used as a base for carbohydrate fermentation studies. The medium has a high level of tryptone making it suitable for use in the indole test. Adjustment of the pH to 8.4 makes the medium an enrichment broth for Vibrio spp.

Plate Count Agar (A.I.D) - (Automatic Inoculation Device) A medium designed for use with the spiral plating system and other surface inoculation techniques. The formula is equivalent to Plate Count Agar A.P.H.A. (3/162) and is suitable for the determination of total viable counts in food products by surface count and pour plate methods.

Plate Count Agar APHA - Formulated to A.P.H.A. specifications, this medium is used for establishing total viable counts for aerobes in food, dairy and water bacteriology. The product uses agar of very high gel strength in order that it can be used in pour-plate as well as surface inoculation techniques. The product can be re-melted prior to use although it should not be held for a prolonged period in the molten stage.

Polymixin B - For the isolation of B. cereus from foods. Suitable for the preparation of 3/408 Bacillus cereus Medium (P.R.E.P.). The addition of 3/1073 sterile egg yolk emulsion is also required.

Positive Syphilitic Control serum - Control reagents for use with Biotec Laboratories VDRL Carbon Antigen.

Potassium Tellurite 3.5% - A sterile solution of 3.5% potassium tellurite. A selective agent for addition to 3/452 Hoyles Medium, for the selective isolation and differentiation of Corynebacterium diptheriae.

Potato Dextrose Agar - Potato Dextrose Agar is recommended by the American Public Health Association for the enumeration of yeasts and moulds in examination of dairy products, soft drinks, dried and frozen foods and other types of product. Depending on whether the medium is to be used as a selective or non-selective agar it can be used with or without acidification.

Progesterone - Indication: Hypothalamic pituitary insufficiency, gonadal insufficiency. Quantitative determination of Progesterone in human serum or plasma. Reaction: 60/15 min, 450nm, 37°C/RT.

Prolactin - Indication: Disease of the human breast, corpus luteum insufficiency, female sterility, hypothalamic pituitary diseases. Quantitative determination of Prolactin in human serum or plasma. Reaction: 30/30/15 min, 450-620nm, RT.

Proteose Peptone A - An enzymatic digest of meat adapted to encourage the production of toxins by Corynebacterium diphtheriae, staphylococci, Salmonella and clostridia. This peptone is highly nutritious and suitable for use in culture media for fastidious organisms such as Neisseria, Haemophilus and Pasteurella species.

Proteus OX19 Antigen - Febrile Antigen for identification and quantification of serum antibodies specific to Proteus OX19 infections. This reagent can be used in either slide titration or tube tests.

Proteus OX2 Antigen - Febrile Antigen for identification and quantification of serum antibodies specific to Proteus OX2 infections. This reagent can be used in either slide titration or tube tests.

Proteus OXK Antigen - Febrile Antigen for identification and quantification of serum antibodies specific to Proteus OXK infections. This reagent can be used in either slide titration or tube tests.

PSA - Determination of Prostate Specific Antigen (PSA) in human serum. Reaction: 30/15 min, 450nm and 620/630nm, RT.

Pseudomonas Agar Base - The base medium is a modification of Kings medium A, which uses magnesium and potassium salts to enhance production of the pigments pyocyanin (green) and fluorescein (detected by U.V./ blue light). The medium can be made generally selective for Pseudomonas species by the addition of C.F.C. supplement (3/1108).

R2A Medium - R2A medium was developed to determine the bacterial count in potable waters during treatment and distribution and has been shown to give significantly higher counts than Plate Count Agar (PCA) or similar high-nutrient media. The standard plate count (SPC) method using PCA provides an enumeration of bacteria which grow best at, or near, body temperature and this estimation at best may correlate to the coliforms present in the sample. However, there will be a population of heterotrophic bacteria which cannot grow at all under the conditions of the SPC method or may grow so slowly that the colonies fail to reach a size detectable to the eye in the 48 hour incubation period. In order to enumerate this section of the bacterial population, in water, a medium of low nutritional content (R2A) and extended incubation times are required. R2A medium is recommended in Report 71, Methods for the Examination of Waters and Associated Materials and Standard Methods for the Enumeration of Water and Wastewater. Image: Heterophylic plate count on R2A medium.

RA Latex test kit - A rapid latex slide agglutination test for the qualitative and semi-quantitative determination of rheumatoid factor in human serum. The presence of these autoantibodies to human IgG is a useful diagnostic tool for active rheumatoid arthritis (RA), as high titres indicate severe disease. The test kit includes the following: RA latex reagent, positive and negative control, test card, pipette stirrers and instructions for use. Results in 2 minutes.

Rappaport Vassiliades (RVS) Medium - Rappaport Vassiliadis Broth (R10 modification) was born out of a long series of experiments carried out to determine the correct levels of malachite green and magnesium chloride that would allow Salmonella to multiply freely yet still inhibit the other enteric organisms. This formulation has been shown to be superior to Mueller Kauffmann and Selenite Broth for the isolation of Salmonella from meat products. The development work carried out on the formulation shows that it is extremely efficient in detecting small numbers of Salmonella in heavily contaminated products. This formulation is very hygroscopic and will produce a slight exothermic reaction when mixed with water.

Reinforced Clostridium Agar - This is a solidified version of Reinforced Clostridium Medium (3/498) and can be used for the enumeration of anaerobes by pour plate, shake tube or membrane filtration methods. When solidified in tubes or bottles with minimal head space it can be used for anaerobic culture without the need for anaerobic atmosphere.

Reinforced Clostridium Medium - This medium was formulated by Hirsch and Grinstead to recover small numbers of Clostridium spp. from a variety of sources. Various workers have reported its efficiency with many products and specimens, R.C.M. is rich, non-selective and uses cysteine hydrochloride and glucose as reducing agents. The small amount of agar reduces diffusion of oxygen through the fluid.

Rh Control - To be used as a control in Rhesus typing with Biotec Rhesus typing antisera when using the slide or tube techniques.

Rose Bengal Chloramphenicol Agar Base - A selective medium for the enumeration of moulds and yeasts in foods. The original formulation of Jarvis (1973) used chlortetracycline. This has been substituted by chloramphenicol because of superior selectivity. The rose bengal dye is taken up by the growing colonies making them easier to see and inhibiting their spreading. Rose bengal becomes increasingly toxic on exposure to light, so it is important to store plates in the dark. Image: Yeast colonies on Rose Bengal Chloramphenicol Agar.

RPR Test kit - This Rapid Plasma Reagin test kit uses a modified form of the VDRL antigen containing microparticulate carbon to enhance the visual reading of positive and negative results. The Biotec Laboratories RPR test kit includes the following: VDRL Carbon Antigen, positive and negative control, needle and dispenser, test cards, pipette stirrers and instructions for use.

Rubella IgG (WHO/IU) - Quantitative determination of IgG antibodies to Rubella virus in human serum or plasma. Reaction: 15/15/5 min, 450nm, RT.

Rubella IgM - Qualitative determination of IgM antibodies to Rubella virus in human serum or plasma. Reaction: 30/30/10 min, 450nm, RT.

Sabouraud Dextrose Agar - Introduced by Sabouraud in 1910 as a selective medium for fungi and yeasts. The acidic pH (5.6) of this medium inhibits many species of bacteria. The medium can be made more selective by the addition of chloramphenicol supplement (3/1009). Diagnostic features, such as sporing structures and pigmentation are well developed on this medium. Because of its low pH this medium is very sensitive to overheating which will soften the agar and caramelise the carbohydrate.

Sabouraud Liquid Medium USP - A liquid sterility test medium for the detection of yeasts, moulds and acidophilic bacteria in pharmaceutical products. This medium conforms with the United States Pharmacopeia. It can also be used as a growth medium for the determination of fungistatic activity in pharmaceutical products.

Sabouraud Maltose Agar - This is a modification of Sabouraud Dextrose Agar (3/168), substituting maltose for dextrose as recommended by the American Public Health Association.

Salmonella H Antigen Group a - Febrile Antigen for identification and quantification of serum antibodies specific to Salmonella H Antigen Group a infections. This reagent can be used in either slide titration or tube tests.

Salmonella H Antigen Group b - Febrile Antigen for identification and quantification of serum antibodies specific to Salmonella H Antigen Group b infections. This reagent can be used in either slide titration or tube tests.

Salmonella H Antigen Group c - Febrile Antigen for identification and quantification of serum antibodies specific to Salmonella H Antigen Group c infections. This reagent can be used in either slide titration or tube tests.

Salmonella H Antigen Group d (Typhi H) - Febrile Antigen for identification and quantification of serum antibodies specific to Salmonella H Antigen Group d infections. This reagent can be used in either slide titration or tube tests.

Salmonella O Antigen Group A - Febrile Antigen for identification and quantification of serum antibodies specific to Salmonella O Antigen Group A infections. This reagent can be used in either slide titration or tube tests.

Salmonella O Antigen Group B - Febrile Antigen for identification and quantification of serum antibodies specific to Salmonella O Antigen Group B infections. This reagent can be used in either slide titration or tube tests.

Salmonella O Antigen Group C - Febrile Antigen for identification and quantification of serum antibodies specific to Salmonella O Antigen Group C infections. This reagent can be used in either slide titration or tube tests.

Salmonella O Antigen Group D (Typhi O) - Febrile Antigen for identification and quantification of serum antibodies specific to Salmonella O Antigen Group D infections. This reagent can be used in either slide titration or tube tests.

Salmonella Vi Antigen - Febrile Antigen for identification and quantification of serum antibodies specific to Salmonella Vi Antigen infections. This reagent can be used in either slide titration or tube tests.

Selenite Broth Base - A medium for the selective enrichment of salmonellae from faeces, food and sewage. First described by Leifson, in 1936, the medium is a peptone lactose broth, moderately buffered, which utilises sodium biselenite as a selective agent. This medium can be incubated at various temperatures from 35 - 43°C to vary the selectivity. Subcultures should be performed after no more than 24 hours incubation as there is an increasing loss of selectivity if incubation is prolonged.

Selenite Cystine Broth - This formulation is a result of the investigation of North and Bartram, in 1953. They examined the effect of varying concentrations of cystine and phosphate on the recovery of salmonellae in egg products using selenite broth. It was found that the addition of 10 micrograms/ml of cystine to Leifsons selenite broth enhanced the recovery of salmonellae.

Sensitivity Test Agar - A medium formulated for antibiotic susceptibility testing by the Joan Stokes technique. S.T.A. is inhibitor-free, very rich and includes various nucleotides to enable fastidious organisms to be tested. It is necessary to add lysed or ‘chocolated’ blood for some organisms. Image: Streptococcus sp. susceptibility test on Sensitivity Test Agar.

Simmons Citrate Agar - A medium devised by Simmons, in 1926, to help in the differentiation of enteric bacteria and in the isolation of fungi. Certain Enterobacteriaceae have the ability to utilise citrate as the sole source of carbon and utilise inorganic ammonium salts as the sole source of nitrogen resulting in an increase in alkalinity. Bromothymol blue is used as a pH indicator.

Slanetz and Bartley Medium - This medium was originally described by Slanetz and Bartley for the enumeration of enterococci from water samples using a membrane filtration technique, but it may also be used as a spread plate for other sample types. Enterococci reduce tetrazolium chloride to the insoluble red dye formazan, producing colonies which are dark red or maroon on the surface of the membrane of the agar. This reaction is not exclusive to enterococci and the count at this stage should be considered presumptive. Colonies may be confirmed as enterococci by demonstrating aesculin hydrolysis using Kanamycin Agar (3/454).

Sodium Biselenite - For use in conjunction with Selenite Broth Base (3/174).

SS Agar - This medium is a modification of Leifsons DCA Medium first described in 1941 by Mayfield and Goeber shortly before Hynes described his modification of DCA. The selectivity of the medium was increased by the addition of extra bile salts, sodium citrate and the addition of brilliant green dye. There is also the extra thiosulphate giving good H₂S production which reduces the ferrous ammonium sulphide giving black centred colonies with H₂S positive organisms. The selectivity of this medium can be such that it was suggested by Taylor et. al., in 1965, to be unsuitable for the isolation of Shigella species. Greater understanding of the selection mechanisms involved enable us to adjust the reaction and allow the more delicate Shigella to grow without unduly impairing the mediums selective properties.

Sulphadiazine for O.P.S.P. - For use with Perfringens agar to prepare O.P.S.P. for the selective isolation of Clostridium perfringens from foodstuffs.

Syphilis rapid device (serum/plasma) - A rapid, one step test for the diagnosis of Syphilis to detect antibodies (IgG and IgM) to Treponema Pallidum (Tp) qualitatively in serum or plasma. The test device contains Syphilis antigen coated particles and Syphilis antigen coated on the membrane.

Syphilis rapid device (serum/plasma/whole blood) - A rapid test for the diagnosis of Syphilis to detect antibodies (IgG and IgM) to Treponema Pallidum (Tp) in serum, plasma or whole blood. The Syphilis rapid device (serum/plasma/whole blood) utilises a double antigen combination of a Syphilis antigen coated particle and Syphilis antigen immobilised on membrane to detect Tp antibodies (IgG and IgM) qualitatively and selectively.

T3 - Indication: Hyper- or Hypo-Thyroidism. Quantitative determination of T3 (Total Triiodothyronine) in human serum. Reaction: 60/15 min, 450nm, RT.

T4 - Indication: Hyper- or Hypo-Thyroidism. Quantitative determination of T4 (Total Thyroxine) in human serum or plasma. Reaction: 60/15 min, 450-620nm, RT.

TCBS Cholerae Medium - T.C.B.S. is designed for the selective isolation of Vibrio species, particularly Vibrio cholerae. The formulation was developed by Kobayashi, Enomoto, Sakazaki and Kuwahara. It inhibits most of the Enterobacteriaceae for at least 24 hours. Therefore heavy inoculation of the medium is possible.

Testosterone - Indication: Hirsutism, virilisation, ovarian tumours, hypothalamic pituitary unit diseases, testicular tumours, prostate cancer, hypopituitarism, Klinefelter´s syndrome, testicular feminisation, orchidectomy. Quantitative determination of Testosterone in human serum or plasma. Reaction: 60/15 min, 450nm, 37°C/RT.

Tetrathionate Broth Base - A selective enrichment broth for the growth of Salmonella typhi and other Salmonella spp. from faeces, foods etc. It conforms to the formulation recommended by the American Public Health Association for use in the examination of dairy products and foods for salmonellae. Organisms which reduce tetrathionate, such as salmonellae, proliferate in the medium, whilst most enteric organisms are inhibited. Certain members of the Proteus group will also reduce tetrathionate thereby impairing the performance of the medium in some cases. To overcome this, novobiocin may be added to the medium at a level of 40 micrograms/ml before addition of the iodine. Gram-positive organisms are inhibited by the inclusion of bile salts.

Thioglycollate Medium (Brewer) - This is the original formula introduced by Brewer, in 1940, as a clear medium for the cultivation of anaerobes. It has found applications as a sterility test medium and as a blood culture medium although it has been superseded by Fluid Thioglycollate Medium (3/445) and Fastidious Anaerobe Broth (3/444) for these purposes. The agar makes the medium viscous slowing down the permeation of oxygen and any convection currents. Sodium thioglycollate acts as a reducing agent and also neutralises the bacteriostatic properties of mercurial compounds. Methylene blue is a redox indicator which is colourless at low Eh (redox potential) but turns blue on exposure to oxygen.

Todd Hewitt Broth - This nutritious broth medium was formulated by Todd and Hewitt for the production of antigenic streptococcal haemolysin. Todd Hewitt Broth is also used to cultivate streptococci prior to serological grouping. The use of a fermentable sugar in the formulation leads to the production of acid which would normally inactivate the haemolysin. This is prevented by the inclusion of buffers to maintain the pH of the medium thus preserving the haemolysin, as well as promoting the growth of pneumococci.

Toxoplasma IgG (WHO/IU) - Quantitative determination of IgG antibodies to Toxoplasma gondii in human serum or plasma. Reaction: 15/15/5 min, 450nm, RT.

Toxoplasma IgM - Qualitative determination of IgM antibodies to Toxoplasma gondii in human serum. Reaction: 15/15/10 min, 450nm, RT.

TPHA Test kit - A confirmatory test for the qualitative and semi-quantitative detection of T. pallidum antibody, based on the passive haemagglutination method (TPHA). Preserved avian erythrocytes are coated with antigenic components of pathogenic T. pallidum, which will bind with specific antibody present in patient’s serum or plasma. The cells are suspended in a medium containing components to eliminate non-specific reactions. The kit contains the following components: Test cells, control cells, diluent, positive and negative controls, instructions for use.

Triple Sugar Iron Agar - This is a modification of the Krumwiede and Kohn medium of 1917 which differentiates some of the Enterobacteriaceae on the basis of four reactions; fermentation of lactose, glucose and sucrose and H₂S production. This medium should be used in conjunction with a urease test to eliminate Proteus spp. when screening for Salmonella spp.

Tryptone - An enzymatic hydrolysate of casein, rich in peptones and amino acids (including tryptophane). This peptone can be utilised by most bacteria as a growth substrate. This peptone conforms to the U.S.P. requirements for a pancreatic digest of casein.

Tryptone Bile Glucoronide Agar - A medium developed for the simple enumeration of Escherichia coli without the need for membranes, or pre-incubation on Minerals Modified Glutamate Medium (3/572). Based upon the formulation of Tryptone Bile Agar (3/524), the medium has been modified by the addition of a chromogenic substrate to detect the B-glucuronidase enzyme, which is highly specific for E. coli*, and is detected by the MUG reagent in other formulations. The advantage of the chromogenic substrate is that it requires no UV lamp to visualise the reaction, and it is concentrated within the colony, facilitating easier enumeration in the presence of other organisms, or when large numbers are present on the plate. * 96-97% of E. coli strains positive. A notable exception is E. coli O157:H7. Image: E. coli on Tryptone Bile Glucuronide Agar.

Tryptone Glucose Extract Agar - A plate count agar suggested by the American Public Health Association (A.P.H.A.) for estimation of total viable counts in food and dairy products. This medium is also recommended by the Association of Official Analytical Chemists (A.O.A.C.).

Tryptone Soy Agar USP - A general purpose agar which will support the growth of a wide range of micro-organisms. The formula conforms with that laid down by the United States Pharmacopeia for sterility testing. The medium can be used for phage typing, colicine typing and for testing the X and V factor requirements of Haemophilus spp.

Tryptone Soy Broth USP - A general purpose nutritious broth capable of growing a wide range of bacteria and fungi. The medium is recommended by the United States Pharmacopeia for the sterility testing of a wide range of pharmaceutical products. The medium is also widely used for blood cultures although the high carbohydrate level may cause rapid growth and subsequent death of acid-producing organisms.

Tryptone Water - A substrate for the testing of an organisms ability to produce indole from tryptophan. The indole test is frequently used in the classification of coliform organisms. This product is preferable to peptone water 3/490 because it has a higher content of tryptophan.

Tryptose Phosphate Broth - This is a versatile nutritionally rich buffered glucose broth. The medium is a general purpose broth that has been used as a blood culture medium, a supplement for animal cell culture, and with the addition of sodium azide 0.025% as a selective medium for streptococci in dairy products.

TSH - Indication: Hypothyroidism, hypothalamic abnormalities. Quantitative determination of TSH (Thyroid stimulating hormone, thyrotropin) in human serum or plasma. Reaction: 60/60/20 min, 450nm and 620nm, RT.

Urea 40% - A sterile solution of 40% urea, for addition fo 3/536 Urea Broth Base and 3/534 Urea Agar Base for the detection of urease production by Proteus spp.

Urea Agar Base - This is a modification of Christensens urea base for the detection of rapid urease production by Proteus spp. Other enterobacteria will split the urea, but this will be delayed. This delay is achieved by the incorporation of glucose and the introduction of a buffering system into the medium. The indicator for ammonia production is phenol red.

Urea Broth Base - This is a liquid version of Urea Agar Base (3/534) introduced by Maslen in 1952. This modification allows inoculation by Pasteur pipette, and it is easier to detect contamination in a fluid rather than in a slope. Maslen also claimed that it is easier to detect positive results.

V.C.A. - Vancomycin, Cefsulodin, Amphotericin, for the isolation of Helicobacter pylori. For addition to Helicobacter pylori medium.

V.C.N.T. for Thayer Martin - Vancomycin, Colistin, Nystatin, Trimethoprim for Thayer Martin Medium. The addition of trimethoprim in V.C.N.T. inhibits the swarming of Proteus spp. which occasionally make interpretation difficult.

VDRL Carbon Antigen - VDRL carbon antigen is a modified form of the VDRL antigen containing micro particulate carbon, which enhances the visual reading of positive and negative results. The reagent can be used for manual or automated (ART) techniques for the qualitative and semi-quantitative detection of reagin antibodies in serum or plasma.

Violet Red Bile Agar - A medium for the enumeration of coliform organisms in food and dairy products. The selectivity of the medium is due to the presence of bile salts and crystal violet. Lactose fermenters produce red/purple colonies often surrounded by a halo of the same colour. Non lactose fermenters produce pale colonies. Selectivity can be increased by incubation at 42-44°C. Image: Coliforms on Violet Red Bile Agar.

Violet Red Bile Glucose Agar - A modification of Violet Red Bile Agar 3/190 introduced by Mossel in 1978. V.R.B.A. 3/190 contains lactose which is fermented by members of the coli/aerogenes group, this medium gives a `coliform count. V.R.B.G.A. 3/538 has substituted lactose with glucose. Glucose is fermented by all members of the Enterobacteriaceae thus V.R.B.G.A. gives a presumptive Enterobacteriaceae count. Bile salts and crystal violet are used to inhibit Gram positive and non-enteric organisms. The overlay procedure ensures anaerobic conditions and suppresses the growth of non-fermentative Gram negative bacteria.

W.L.Nutrient Agar - This medium was developed by Green and Gray in 1950 for the isolation and enumeration of yeasts, moulds and bacteria in the brewing process. The medium has a pH of 5.5 which is optimum for Brewers yeast and will allow the growth of a wide range of organisms including Enterobacteriaceae, Flavobacteria, Lactobacillus and Pediococcus spp. as well as yeasts and moulds. If a process involving bakers or distillers yeast is under examination the pH should be adjusted to 6.5. The medium may be adapted to detect bacteria only by the addition of 0.004 g/litre of Actidione to suppress the yeasts.

Wort Agar - A medium for the enumeration of yeasts and moulds in butter, developed by Parfitt in 1933. The medium can be modified to enable it to isolate osmophilic yeasts from soft drinks and sugar products by the addition of high concentrations of sucrose and glucose.

XLD Agar - This medium was introduced by Taylor in 1965 to improve the recovery and recognition of Shigella spp, it has proved to be an excellent medium for Salmonella spp. The medium is low in nutrients and relies on a small amount of Sodium desoxycholate for selectivity. The indicator system is novel and complex. Most enteric organisms except Shigella, will ferment xylose to produce acid however the Salmonellae will also decarboxylate the lysine to keep the pH neutral. At near neutral pH the salmonella can produce H2S from the reduction of thiosulphate producing black or black centred colonies. Citrobacter spp. can also decarboxylate lysine, however the acid produced by fermentation of both lactose and sucrose will keep the pH too acid for H₂S to be produced. Image: Mixed organisms on XLD Agar.

Yeast Extract (Powder) - Prepared by the autolysis of Saccharomyces cerevisae under thermostatically controlled conditions to protect the B vitamins and other heat labile constituents. This extract provides a mixture of amino acids, peptides, vitamins and carbohydrates making it suitable for many applications.

Yeast Extract Agar - A nutrient agar corresponding to the Standard Formulation for the plate count of micro-organisms in water and dairy products. This medium is also useful for teaching and demonstrating purposes using non-fastidious organisms.

Yeast Extract Chloramphenicol Agar - A selective medium for the enumeration of yeasts and moulds in milk and other dairy products. The formulation meets the requirements of the International Milk Union (1980), the International Organisation for Standardisation (I.S.O.) and the British Standards Institute (B.S.I.). The medium is said to have superior storage properties to O.G.Y.E. and also has the advantage of incorporating an autoclavable supplement.

Yersinia CIN Agar Base - This medium is based on the work of Schiemann. It is used for the isolation and enumeration of Yersinia spp. from clinical samples and from food. The selective components are sodium desoxycholate, crystal violet, cefsulodin, irgasan and novobiocin. Yersiniae ferment mannitol with an intense, localised, acid production in the centre of the colony which produces a red `bulls eye appearance. The ratio of transparent border to red centre varies with serotype and environmental strains may appear rough with an irregular edge. Most other enteric bacteria, if they grow produce a larger colony with a diffuse pinkish centre and opaque outer zone.