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Sorbitol MacConkey agar is a differential medium for the isolation of Escherichia coli 0157:H7 based on the formulation by Rappaport and Henig. It differs from other MacConkey mediums in that lactose has been replaced by sorbitol. As Escherichia coli 0157:H7 does not ferment sorbitol it produces pale translucent colonies whereas most other strains of Escherichia coli are sorbitol positive and produce pink colonies. Although it should be noted that colonies that are sorbitol positive can revert and possibly be mistaken as sorbitol negative. Tryptone and meat peptone provide the required carbon, nitrogen and vitamins. Sorbitol is a fermentable carbohydrate and neutral red is a pH indicator. Bile Salts no.3 and crystal violet are selective agents and together inhibit Gram-positive cocci. Sodium chloride maintains the osmotic balance. If required, the selectivity of the medium may be increased by the addition of cefixime (0.05mg/L) and potassium tellurite (2.5mg/L). Related Supplements : LS0013 Escherichia coli 0157 Selective Supplement -
Soy peptone is manufactured from the enzymatic hydrolysis of soybean. This product provides a good source of nitrogen, carbohydrates, and vitamins. It is recommended for use in microbiological media for the detection and isolation of a wide variety of bacteria and fungi.
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E&O Heat Inactivated Serum is derived from horse serum and is suitable for use in diagnostic assays. One of the reasons for the heat inactivation of serum (heating to 56°C for 30 min) is to inactivate complement, a group of proteins present in serum that are part of the immune response. This is sometimes important for cells that will be used to prepare or assay viruses, used in cytotoxicity assays or other systems where complement may have an unwanted influence. The use of Heat Inactivated Serum is also usually recommended for growing embryonic stem cells. After filtration the dispensing and bottle filling processes are carried out in a state-of-the-art clean room under laminar flow. Once labelled the filled bottles are then subjected to controlled heat inactivation and are frozen and stored at -20°C without delay. The filter sterile Heat Inactivated Horse Serum is supplied in 100 or 500 ml PETG bottles. All E&O products are for in vitro use only. E&O products are intended only for use by qualified professionals who will safely handle and dispose of products they receive. All biologically derived materials (e.g. blood, sera) should be handled as if a potential biohazard. E&O media that contain antibiotics should be handled with care. Chemical resistant gloves, eye protection and laboratory coat should be worn. -
All E&O products are for in vitro use only. E&O products are intended only for use by qualified professionals who will safely handle and dispose of products they receive. All biologically derived materials (e.g. blood, sera) should be handled as if a potential biohazard. E&O media that contain antibiotics should be handled with care. Chemical resistant gloves, eye protection and laboratory coat should be worn. -
Thiosulphate Citrate Bile Salts Sucrose (TCBS) Agar is a selective isolation medium for culture of pathogenic Vibrio spp. from clinical and food samples. The formulation was developed by Kobayashi et al. which was modified from Nakanishi’s formulation. Vibrio species are most widely recognized for their role in human intestinal infections and cholera worldwide. Thiosulphate Citrate Bile Salts Sucrose (TCBS) Agar is recommended by the FDA BAM, the UK Standards for Microbiology Investigations, and complies with the standard laid out by ISO 21872.
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Trichomonas medium is based on the formula described by Kupferburg, Johnson and Sprince for the selective isolation of Trichomonas spp. (1) The tryptone and liver extract act as carbon, nitrogen and vitamin sources in this medium. Maltose is a fermentable carbohydrate. The agar and cysteine HCl reduce the oxygen tension in the medium which aids the growth of trichmonads. Methylene blue is a redox indictor and allows for the visualisation of any significant oxygen diffusion in the medium. The addition of selective agents such as chloramphenicol is recommended to inhibit bacterial species that may be present in specimens. References 1) Kupferberg, A.B. Johnson, G., and Sprince, H. 1948. Proc. Soc. Exper. Biol. Med., 67:304-308
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Triple sugar iron agar is used to differentiate between some of the enterobacteriacae on the basis of four reactions: fermentation of lactose, glucose and sucrose and the production of hydrogen sulphide. Beef extract, yeast extract and peptone provide the required nitrogen, carbon and vitamins. Lactose, sucrose and glucose are carbohydrates. Acid production from their fermentation is detected by the phenol red pH indictor. Sodium thiosulphate is reduced to hydrogen sulphide which is detected by the ferric citrate indicator. Sodium chloride maintains osmotic balance.
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Tryptone is obtained by pancreatic digestion of casein. Casein is the main protein of milk and is a rich source of amino acid and nitrogen. This product can be used in preparing microbiological culture media providing nitrogen, vitamins, minerals and amino acids. Due to the high tryptophan content in tryptone it can be used in detecting indole production.
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Recent developments in culture media have given rise to the use of chromogenic substrates as a means of differentiating bacteria particularly among the coliform group of organisms. This is one such medium and has been developed as a selective medium for the isolation and enumeration of Escherichia coli without the need for membranes or pre-incubation. Based on the formulation of Tryptone Bile Agar it incorporates a chromogenic substrate, X-Glucuronide, to detect the ß-glucuronidase enzyme which is specific for the majority of E. coli strains. Approximately, 3-4% of E. coli are glucuronidase negative including E. coli O157.(1) The advantage of the chromogenic substrate is that the reaction is concentrated within the colony resulting in distinctive blue/green colonies of E. coli while the other coliforms produce cream colonies. The tryptone provides the required carbon, nitrogen and vitamins. Bile salts No.3 is a selective agent against Gram-positive bacteria. X-glucuronide is a chromogenic substrate. Agar is solidifying agent.
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Tryptone Soya Agar is used for a wide range of applications, including culture storage, enumeration of cells, isolation of pure cultures, or simply general culture. It has been found to be useful in cosmetic testing, water, and wastewater applications. Tryptone Soya Agar may be used to determine X and V factor requirements of Haemophilus species; sterility testing; and environmental monitoring within pharmaceutical cleanrooms and sterile facilities. This medium meets the requirements of the Harmonized USP/EP/JP and is based on the original formulation described by Leavitt et al. in 1955. Tryptone Soya Agar is recommended as a reference medium when testing selective media, to measure the degree of inhibition. In environmental monitoring applications, it is common for plates to be incubated at 30-35°C for bacterial colonies and 20-25°C for mould and fungi. Tryptone Soya Agar will support the growth of both aerobic and anaerobic organisms depending on incubation conditions. KM0024 unsupplemented is recommended by the World Health Organization, UK Standards for Microbiology Investigations, International Organization for Standardization and is tested in accordance with ISO 11133:2014. This medium is also included in the Bacteriological Analytical Manual for cosmetics testing. UK Standards for Microbiology Investigations also call for Tryptone Soya Agar supplemented with 5% sheep blood (E&O DSC) for aid in the identification of Bordetella species from clinical specimens. The addition of defibrinated animal blood to the base medium, promotes the growth of most fastidious organisms and presumptive identification can be made based on haemolytic reactions. It should be noted that the haemolytic patterns of isolates may vary with the source of animal blood. Addition of selective agents allows isolation and presumptive identification of specific species or groups of organisms. Related Supplements : Defibrinated Sheep Blood, Defibrinated Horse Blood
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A general purpose and nutritious medium for the non-selective enrichment of non-fastidious and some fastidious organisms. Tryptone and soy peptone are the nitrogen and vitamin source in the medium. Glucose is the carbon energy source that facilitates organism growth and sodium chloride maintains osmotic balance. Di-potassium hydrogen phosphate is a buffering agent to prevent auto-sterilisation due to acid production during the growth of some organisms. Tryptone Soya Broth is also commonly referred to as Soybean-Casein Digest Medium or Tryptic Soya Broth and is abbreviated as TSB. TSB conforms to the Harmonized United States Pharmacopoeia (USP), European Pharmacopoeia (EU), and Japanese Pharmacopoeia (JP).
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A modification of Christensens medium by Maslen this medium is generally used to detect rapid urease activity of Proteus spp. It can also be used to detect urease activity of other enterobacteriaceae including urease producing Salmonella spp. and Shigella spp. When used for the latter purpose it is necessary to increase the incubation time to as long as 48 hours. The peptone provides the required nitrogen, carbon and vitamins. Glucose is a fermentable carbohydrate. The potassium dihydrogen phosphate is a buffer and sodium chloride maintains osmotic balance. Phenol red is a pH indicator. Related Supplements : BM3000 Urea 40% Solution
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A modification of Christensens medium by Maslen this medium is generally used to detect rapid urease activity of Proteus spp. although it can be used to detect urease activity of other enterobacteriaceae including urease producing Salmonella spp. and Shigella spp. Unlike Christensens medium when used for the later purpose it is not necessary to increase the incubation time. The peptone provides the required nitrogen, carbon and vitamins. Glucose is a fermentable carbohydrate. The disodium phosphate and potassium dihydrogen phosphate are buffers and sodium chloride maintains osmotic balance. Phenol red is a pH indicator. Related Supplements : BM3000 Urea 40% Solution
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Violet Red Bile Agar is a medium for the enumeration of coliform organisms in food and dairy products and conforms to American Public Health Association (APHA). Yeast extract and enzymatic digest of gelatin provides the required carbon, nitrogen and vitamins. Sodium chloride maintains the osmotic balance. The medium is made selective by the inclusion of bile salts and crystal violet to inhibit Gram-positive and non-enteric organisms. Lactose is a fermentable carbohydrate and neutral red is a pH indicator. 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 42-44ºC.
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Violet Red Bile Glucose Agar (VRBGA) is a selective medium for the isolation and enumeration of Enterobacteriaceae in food products. It is a modification of the original Violet Red Bile Agar with the lactose being replaced with glucose. As all Enterobacteriaceae ferment glucose VRBGA allows for a wider range of organisms to be detected. This medium conforms to the requirements of the Harmonised USP/EP/JP. Yeast extract and pancreatic digest of gelatin provide the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate and neutral red is a pH indicator. Sodium chloride maintains the osmotic balance. The medium is made selective by the inclusion of bile salts and crystal violet to inhibit Gram-positive and non-enteric organisms.
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KM0013 Xylose Lysine Deoxycholate (XLD) Agar is used for the isolation and detection of Salmonella and Shigella spp. in clinical specimens, food, and environmental samples. Xylose Lysine Deoxycholate (XLD) Agar is used for the isolation of Salmonella from food and animal feedstuffs when used according to ISO 6579:2017, ISO 11133:2014. The formulation conforms to CLSI M22 and European, United States and Japanese Pharmacopeia requirements. KM0013 is recommended for clinical specimens as a standard, supplementary or primary isolation medium by the UK Standards for Microbiology Investigations. Xylose Lysine Deoxycholate (XLD) Agar has a pH of 7.4, leaving it with a bright red appearance due to the indicator phenol red. Sugar fermentation lowers the pH and the phenol red indicator registers this by changing to yellow. Most gut bacteria, including Salmonella spp., can rapidly ferment the sugar xylose to produce acid; Shigella spp. cannot do this and therefore remain red. Once the xylose has been used, Salmonella spp. decarboxylate lysine leading to a reversion to an alkaline pH. Additionally, Salmonella spp. (but not Shigella species) are able to reduce thiosulphate to hydrogen sulphide which reacts with ferric ions to produce the black pigment iron sulphide. Salmonella spp. may, therefore, be differentiated since colonies have a black centre on this medium.
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Yeast extract is obtained from selected autolyzed Saccharomyces cerevisiae cells. This product can be used in preparing microbiological culture media providing readily available soluble vitamins (notably B-complexes), amino acids, peptides, and other essential growth factors. Yeast extract is observed as an animal free source and is therefore used extensively in many non-animal cell culture formulations.
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Yeast extract agar is a nutrient rich medium for the cultivation of non-fastidious bacteria, yeasts and moulds. Recommended for the plate count of microorganisms in water and dairy products. The yeast extract and peptone acts as a source of nitrogen, amino acids, carbon and vitamins. Related Supplements : LS0019 Oxytetracycline Selective Supplement
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This is a selective medium for the isolation and enumeration of yeasts and moulds in dairy products. It is in according to a typical formulation of The International Organisation for Standardisation (ISO). Yeast extract acts as a source of nitrogen, carbon and vitamins in this medium. Glucose is a fermentable carbohydrate. Although the medium has a low pH it is made more selective by the inclusion of chloramphenicol, an antibiotic selective agent.
