-
Alkaline peptone water is generally used as an enrichment medium in the isolation of Vibrio spp. from faeces. This medium may also be used for the enrichment of Vibrio spp. from food and water samples. First developed by Shread, Donovan and Lee as an enrichment broth for the growth of Aeromonas spp., Cruickshank showed that with a higher pH the medium can be used for the enrichment of Vibrio spp. The peptone is the source of the required nitrogen, carbon and vitamins. Sodium chloride maintains the osmotic balance. The high pH of the medium inhibits most enteric organisms for at least 24 hours. -
Beef extract is sourced from bovine tissue and supports the nutritive needs of microorganisms. Providing a mixture of amino acids, peptides, minerals and vitamins this product is recommended for use in microbiological culture media for the examination of water, milk and other materials.
-
Blood agar base No. 2 is a general-purpose medium enriched with various concentrations of horse or sheep blood and is suitable for the isolation of most organisms including many fastidious anaerobes of clinical significance. Haemolysis observations may vary with the type of blood being used. Previous studies have shown that sheep blood provides the most reliable colony and haemolysis characteristics. The peptone, yeast extract and liver digest act as nitrogen, carbon and vitamin sources in this medium. Sodium chloride maintains osmotic balance. Related Supplements : Defibrinated Sheep Blood, Defibrinated Horse Blood, LS0008 Staph/Strep Selective Supplement, LS0017 Neomycin Selective Supplement
-
Brain heart infusion agar is very nutritious general-purpose medium and is suitable for the isolation of most micro-organisms including many fastidious organisms. The formulation is a modification of that from Rosenow and Hayden. The medium is not recommended for the determination of haemolytic reactions because of the glucose content. The nitrogen, vitamin and carbon sources are supplied by the Brain-Heart infusion solids and peptone. Glucose serves as the carbohydrate source and sodium chloride aids in maintaining the osmotic balance. A phosphate buffer, disodium hydrogen phosphate, is incorporated to help neutralize any acids produced as a result of glucose utilization and thus maintain viability of the organisms. NB: Organisms that produce large amounts of acid in the medium may overwhelm the buffering system and as a result may ‘auto-sterilize’ the culture.
-
Brain heart infusion broth is very nutritious isotonic medium with a low concentration of glucose to stimulate early growth. The formulation is a modification of that from Rosenow and Hayden. Brain heart infusion broth is suitable for the isolation of most micro-organisms including many fastidious organisms and, with the appropriate enrichment, is suitable as a base for blood culture medium. The nitrogen, vitamin and carbon sources are supplied by the Brain-Heart infusion solids and peptone. Glucose serves as the carbohydrate source and sodium chloride aids in maintaining the osmotic balance. A phosphate buffer, disodium hydrogen phosphate, is incorporated to help neutralize any acids produced as a result of glucose utilization and thus maintain viability of the organisms. NB: Organisms that produce large amounts of acid in the medium may overwhelm the buffering system and as a result may auto-sterilize the culture.
-
Brain-heart infusion solids is a dehydrated infusion of porcine brains and heart. This product can be used in preparing microbiological culture media providing nitrogen, vitamins, minerals and amino acids.
-
Burkholderia cepacia agar base is a selective medium for the detection and isolation of Burkholderia cepacia from cystic fibrosis (CF) patients. This is an important opportunistic pathogen in CF patients and can lead to fatal infection in approximately 20% individuals that have been colonised with B. cepacia complex organisms. This medium is based on the PC medium described by Gilligan et al. Magnesium sulphate, ammonium sulphate and ferrous ammonium sulphate supports the growth of B. cepacia. Potassium di-hydrogen phosphate and di-sodium hydrogen phosphate are buffering agents, used to maintain the pH the medium. The phenol red is used as a pH indicator. If the sodium pyruvate in the medium is metabolised by B. cepacia alkaline by-products are produced which raises the pH. This causes the colour of the medium to turn pink/red around sections of heavy growth on the medium. Bile salts and crystal violet are selective agents. The associated selective supplement for this medium, LS0125, contains ticarcillin and polymyxin B which further improves the selectivity, particularly with the inhibition of Pseudomonas spp. Related Supplements : LS0125 B.cepacia Selective Supplement, LS0026 Pseudomonas CFC Selective Supplement
-
This is one of several selective media available for the isolation of Campylobacter spp. in clinical, food and environmental laboratories. Campylobacter agar base is based on the formulation from Bolton and Robertson. The peptone is the source of the required nitrogen, carbon and vitamins. Sodium chloride maintains the osmotic balance in the medium. The medium is enriched with lysed horse blood and made selective by the addition of cefoperazone, to suppress other enteric organisms, and amphotericin to suppress yeast and fungal growth (Preston supplement LS0010). Related Supplements : LS0009 Campylobacter (Skirrow) Selective Supplement, LS0010 Campylobacter (Preston) Selective Supplement, Lysed Blood
-
This medium is based on the formulation published by Platt, Atherton & Simpson1 and is used for the cultivation of Taylorella equigenitalis, the causative organism in contagious equine metritis. It is routinely used for culturing swabs taken from the genitalia of mares and stallions. Enzymatic digest of casein and soy peptone supply nitrogen, carbon and vitamins and L-cystine is a required growth factor. Sodium chloride provides osmotic balance and sodium sulphite is present as a reducing agent. The medium is made selective by the addition of CEMO Selective Supplement (LS0041) to control bacteria and fungi from swab samples. References 1. Platt, H., Atherton, J. G. and Simpson, D. J. 1978. Equine Vet J 10, 153–159.
-
This medium is used for the cultivation and enumeration of Lactobacillus spp. MRS agar is based on the formulation by de Man, Rogosa and Sharpe. The peptone, yeast extract and beef extract provides the reuired carbon, nitrogen and vitamin source. Glucose is a fermentable carbohydrate. The magnesium sulphate and manganese sulphate act as growth stimulants. Potassium phosphate is a buffering agent. Selectivity of the medium is achieved through the use of ammonium citrate and sodium acetate, inhibiting microorganisms such as streptococci and moulds. The addition of the surfactant Tween 80 is required to facilitate the uptake of nutrients from Lactobacillus spp.
-
A selective medium for the isolation and detection of dermatophytic fungi originally developed by Taplin et al. Dermatophytes appear as fluffy colonies with reddening of the medium while other fungi cause the medium to become yellow due to acid production. Yeasts will also grow on this medium but are readily distinguished by their distinct white/creamy colonies and distinctive smell. Soy peptone provides the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate. The inclusion of phenol red assists in the differentiation between saprophytic and environmental fungi. Although the low pH (pH 5.5) of the medium inhibits most bacteria chloramphenicol and cycloheximide are often added to further reduce the risk when processing material that may be more heavily contaminated. NB: Prolonged incubation should be avoided as this may cause fungi other than dermatophytes to turn the medium red. Related Supplements : LS0050 Chloramphenicol Selective Supplement
-
DNase agar is used primarily in clinical laboratories to differentiate pathogenic Staphylococcus aureus from other staphylococci based on deoxyribonuclease (DNase) activity. The tryptone provides the required carbon, nitrogen and vitamins. Sodium chloride maintains the osmotic balance. The addition of DNA to the base medium provides a simple method to check for DNase activity. Following incubation of the inoculated medium, the surface of the medium is flooded with a small quantity of 1M hydrochloric acid to precipitate the DNA. This results in the medium turning opaque. Organisms that can produce sufficient quantity of a DNase enzyme will hydrolyse the DNA resulting in a clear area around the colonies. Whereas DNase negative organisms will not produce clearing. NB: As with most tests of this type a positive result should not be taken in isolation and other appropriate tests, e.g. coagulase test, latex agglutination etc., should be carried out.
-
DNase agar is used primarily in clinical laboratories to differentiate pathogenic Staphylococcus aureus from other staphylococci based on deoxyribonuclease (DNase) activity. The tryptone provides the required carbon, nitrogen and vitamins. Sodium chloride maintains the osmotic balance. The addition of DNA to the base medium provides a simple method to check for DNase activity. The methyl green fades into a colourless compound if the DNA in the medium is depolymerised. Organisms that can produce sufficient quantity of a DNase enzyme will hydrolyse the DNA resulting in a clear area around the colonies. Whereas DNase negative organisms will not produce clearing. NB: As with most tests of this type a positive result should not be taken in isolation and other appropriate tests, e.g. coagulase test, latex agglutination etc., should be carried out.
-
E.E. Broth is recommended as an enrichment medium when examining food and feedstuffs for Enterobacteriaceae. It is a modification of Brilliant Green Bile Broth, with an improved buffering capacity to encourage early growth and prevent autosterilization. E.E. Broth uses glucose instead of lactose to make the medium a test for all enterobacteria including non-lactose fermenting organisms. This formulation complies with the Harmonized USP/EP/JP. Nitrogen is supplied by the gelatin peptone whilst glucose serves as the fermentable carbohydrate source. Oxbile and brilliant green are the selective agents helping to suppress Gram-positive non- target organisms. Auto sterilisation is prevented through the buffer system composed of potassium dihydrogen phosphate and disodium hydrogen phosphate.
-
This medium is for the growth of fastidious anaerobes, particularly Bacteroides spp. Fastidious anaerobe broth is also suitable for anaerobic blood culture. The peptone and yeast extract provides the required carbon, nitrogen and vitamins. Haemin, vitamin k and L-cysteine HCl are growth factors required by some anaerobes. Sodium thioglycollate and L-cysteine HCl reduce the Eh of the medium and the agar helps maintain the Eh. Resazurin is a redox indicator and sodium chloride maintains the osmotic balance. NB: For best results it is recommended that the medium be heated in a boiling water bath, with the cap loosened, and then allowed to cool, with the cap tightened, immediately before use. The cap must be replaced on the container immediately after inoculation.
-
Hoyles agar is selective culture medium for the isolation and differentiation of Corynebacterium diphtheriae types. Hoyles agar allows for rapid growth of the organisms and normally 18 hours incubation should be sufficient for a diagnosis. As the medium is highly selective, inoculation should be by rubbing the swab (or other material) over the entire surface of the agar, there is no need to spread the inoculum with a loop indeed doing so can cause the organism to be missed especially when they are present only in small numbers. The Elek method can be used to determine the toxigenicity of any C. diptheriae strains. The beef extract and peptone act as a source of nitrogen, carbon and vitamins. The sodium chloride maintains osmotic balance. This medium should be used in conjunction with two supplements: lysed horse blood at 50 ml/l and 10ml/l of potassium tellurite 3.5% solution (BM2230). Lysed horse blood provides added nutrients to the medium and potassium tellurite inhibits Gram-negative and several Gram-positive microorganisms. Related Supplements : BM2290 3.5% Potassium Tellurite Solution, Horse Blood Lysed
-
Thiosulphate citrate bile salts sucrose (TCBS) agar is a selective medium used in microbiology laboratories to isolate Vibrio spp. The formulation was developed by Kobayashi et al. which was modified from Nakanishi’s formulation. The yeast extract and peptone are the source of the required nitrogen, carbon and vitamins. TCBS agar contains high concentrations of sodium thiosulphate, sodium citrate and ox bile to inhibit the growth of Gram-positive organisms and suppress coliforms. Sucrose is included as a fermentable carbohydrate for the metabolism of Vibrio spp. Sodium chloride maintains the osmotic balance in the medium. Sodium thiosulphate also serves as a sulphur source and, in combination with ferric citrate, detects hydrogen sulphide production. Thymol blue and bromothymol blue are included as indicators of pH changes.
-
Lactalbumin hydrolysate is obtained through enzymatic hydrolysis of lactalbumin protein in milk whey. This product is rich in essential amino acids as well as providing a source of nitrogen, carbon and vitamins. It is commonly utilized in media for tissue culture and for the production of vaccines as well as being useful for bacterial and fermentation media.
-
Lactose broth is used for the performance and confirmation of the Presumptive Test for coliforms in water and dairy samples. This medium is also frequently used as a pre-enrichment medium when testing foods, water samples and dairy products for Salmonella spp. Beef extract and gelatin peptone provide the required carbon, nitrogen and vitamins in this medium. Lactose is a fermentable carbohydrate. Fermentation of lactose is detected by the production of gas
-
Luria Bertani (LB) broth is used for the cultivation and maintenance of recombinant strains of Escherichia coli for molecular biology procedures. LB broth (Lennox) contains half of the amount of sodium chloride found in LB broth (Miller). Enzymatic digest of casein provides the required nitrogen and carbon. Vitamin B complex required by recombinant strains of Escherichia coli are supplied by yeast extract. Sodium chloride maintains the osmotic balance and provides sodium ions for membrane transport.
-
Luria Bertani (LB) broth is used for the cultivation and maintenance of recombinant strains of Escherichia coli for molecular biology procedures.(1) Enzymatic digest of casein provides the required nitrogen and carbon. Vitamin B complex required by recombinant strains of Escherichia coli are supplied by yeast extract. Sodium chloride maintains the osmotic balance and provides sodium ions for membrane transport.
-
Listeria isolation medium (Oxford) is based on the formulation described by Curtis et al. and is used for the isolation and identification of Listeria spp. in food and clinical laboratories. Columbia agar base provides the required carbon, nitrogen and vitamins in the medium. Lithium chloride is included to inhibit enterococci. Aesculin is present as an indicator; Listeria spp. will hydrolyse aesculin and the associated reaction with the ferric ammonium citrate gives rise to a black precipitate around the colonies. Selectivity is enhanced by addition of Listeria Oxford selective supplement (LS0030). This contains acriflavine, cefoxitin, colistin, fosfomycin and amphotericin to inhibit any yeasts present and some other Gram-positive and Gram-negative organisms that may be present in specimens. Related Supplements : LS0030 Listeria Oxford Selective Supplement
-
MacConkey agar No. 3 is a selective medium primarily for the isolation of Enterobacteriacae from waters and sewage. This media differs from the original MacConkey formulation in that as well as bile salts, crystal violet has been included as an additional selective agent. This has the effect of inhibiting Gram-positive organisms. The peptone acts as a nitrogen, carbon and vitamin source. Sodium chloride maintains osmotic balance. Lactose is a carbohydrate and during its fermentation causes a confined pH drop around the bacterial colony. This causes a colour change in the pH indicator, neutral red and bile precipitation.
-
This is a selective medium for the isolation and differentiation of bile tolerant Gram-negative (enteric) and Gram-positive (staphylococci and enterococci) organisms and has uses in all areas of bacteriology. This medium is recommended by the World Health Organisation and the Department of Health for the bacteriological examination of water. It has the disadvantage that many strains of Proteus spp. will spread on it and for this reason MacConkey Agar without salt and crystal violet may be preferred (KM0011).
-
A selective medium for the enrichment of Enterobacteriaceae and the detection of Escherichia coli in pharmaceutical products. The inclusion of bromocresol purple indicator makes the colour change caused by acid production from the fermentation of lactose easy to read with gas formation. The presence of ox bile helps to suppress the growth of Gram-positive and non-enteric bacterial species. This formulation complies with the Harmonized USP/EP/JP. Nitrogen is supplied by the gelatin peptone whilst lactose serves as the fermentable carbohydrate source. Oxbile is the selective agent helping to suppress Gram-positive organisms and bromocresol purple detects the pH change as a result of the fermentation of lactose.
-
Malt extract is sourced from hydrolyzed vegetal protein. Due to the high concentration of carbohydrate malt extract is particularly suited for the cultivation of yeasts and moulds especially in contaminated dairy products. In microbiological culture media it provides a source of nutrients, protein, and carbon.
-
Malt extract agar is used for the detection, isolation and enumeration yeasts and moulds. The high carbohydrate content of the medium ensures rapid growth of yeasts and moulds. Malt extract and mycological peptone provide the carbon, protein and nutrient sources required by the organisms. The acidic nature of this medium allows for optimal growth of moulds and yeasts while restricting bacterial growth. Malt extract agar can also be used for the cultivation of fungi, although with the prolonged incubation necessary, cultures may become overgrown by bacteria. The selectivity of the medium can be increased by lowering the pH to 3.5-4.0 or by the addition of selective agents such as chloramphenicol. Related Supplements : LS0050 Chloramphenicol Selective Supplement
-
Malt extract broth is used for the cultivation of yeasts and moulds and is commonly used as part of sterility testing protocols. The high carbohydrate content of the medium ensures rapid growth of yeasts and moulds. Malt extract and mycological peptone provide the carbon, protein and nutrient sources required by the organisms. The acidic nature of this medium allows for optimal growth of moulds and yeasts while restricting bacterial growth.
-
Meat peptone is sourced from hydrolyzed proteins of animal tissue. This peptone consists of soluble amino acids and peptides that provide readily available nitrogen and other essential growth factors. It is primarily used for the cultivation of fastidious and non-fastidious microorganisms in microbiological culture media.
-
A basic general-purpose medium suitable for use in the cultivation of the less fastidious organisms particularly those that do not require the addition of blood or other enrichment. When used to prepare agar slopes or agar butts, the medium can be used to maintain control organisms. The peptone provides the required carbon, nitrogen and vitamins. Sodium chloride maintains osmotic balance.
-
Palcam agar is a selective differential medium for the isolation of Listeria monocytogenes from food, clinical and environmental specimens. The Columbia peptone mix and starch provide the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate. Differentiation of Listeria spp. from enterococci and staphylococci occurs through aesculin hydrolysis and mannitol fermentation. Listeria monocytogenes will hydrolyse aesculin and the associated reaction with the ferric ammonium citrate gives rise to a brown/black precipitate around the colonies. Listeria spp. do not however ferment mannitol. Mannitol fermentation is seen through a colour change of the colony or the area around the colony from red to yellow due to the production of acidic end products. Phenol red is the pH indicator in the medium. Lithium chloride is included to inhibit enterococci. The associated Palcam selective supplement, LS0038, contains polymyxin B, acriflavine and ceftazidime to inhibit other Gram-positive and Gram-negative organisms that may be present in specimens. Related Supplements : LS0038 PALCAM Selective Supplement
-
Peptone water is a general-purpose medium that supports thecultivation of non-fastidious organisms. This non-selective medium can be used a basal medium for biochemical tests such as carbohydrate fermentation and production of indole. Tryptone and peptone act as sources of carbon, nitrogen and vitamins in this medium and sodium chloride maintains osmotic balance.
-
Perfringens Agar Base is a base medium that allows the enumeration of Clostridium perfringens from food samples. As a base medium, Perfringens Agar Base can have several supplementary and selective agents added to increase selectivity. The addition of Eye Yolk Emulsion (BM0140) allows the detection of lecithinase activity as precipitates are formed by C. perfringens. The addition of D-cycloserine (LS0023) can be used to inhibit other facultative anaerobes, as used in Tryptose-Sulphite-Cycloserine (TSC) agar. (1&2) Alternately, kanamycin and polymyxin B (LS0025) can be used to inhibit other coliforms generally found in food samples, as used in Shahidi-Ferguson Perfringens (SFP) agar.(3) The tryptose and soy peptone provide the required nitrogen, carbon and minerals. Yeast extract provide the essential vitamins, including the vitamin B group, needed for growth. The ferric ammonium citrate and sodium metabisulphite allows the reduction of sulphites to hydrogen sulphide by C. perfringens, which produces black colonies. References (1) ISO- 7937:2004. Microbiology of food and animal feeding stuffs- Horizontal method for the enumeration of Clostridium perfringens - Colony count technique (2) Harmon, S.M., Kauttar, D.A. and Peeler, J.T. 1971. Improved Medium for Enumeration of Clostridium perfringens. Appl. Microbiol. 22:688-692. (3) Shahidi S. A. and Ferguson A. R. 1971 New Quantitative, Qualitative, and Confirmatory Media for Rapid Analysis of Food for Clostridium perfringens. Appl. Microbiol. 21:500-506
-
Plate Count Agar is formulated to the A.P.H.A. specification developed by Buchbinder et al. This medium is intended for use in food, dairy and water bacteriology to perform Total Viable Counts. Tryptone and yeast extract provide the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate.
-
Primary Membrane Lactose Glucuronide Agar (mLGA) is used for the differentiation and enumeration of Escherichia coli and other coliforms through a single membrane filtration technique. The peptone and yeast extract provide the required nitrogen, carbon and vitamins. Sodium pyruvate protects injured cells enhancing recovery and growth of coliforms. Sodium lauryl sulphate is a selective agent that inhibits Gram-positive organisms. Lactose is a fermentable carbohydrate and phenol red is a pH indicator. Lactose fermentation will result in yellow colonies. X-glucuronide is a chromogenic substrate which can be cleaved by the enzyme ß-glucuronidase present in E. coli. This results in a blue colony, but in combination with lactose fermentations colonies will appear green. NB: Prepared plates stored at 28°C may show formation of surface crystals which will disappear when plates are warmed to >20°C Related Supplements :
-
This is a selective medium for the isolation of Pseudomonas spp. primarily in food, water and environmental samples. Pseudomonas agar base is on Kings A medium which uses magnesium and potassium salts to enhance pigment production. The gelatine peptone and acid hydrolysed casein acts as a nitrogen, vitamins, and carbon source. Magnesium chloride and potassium sulphate promotes production of pyocyanin. The medium can be made selective for P. aeruginosa by the addition of Pseudomonas CN Supplement (LS0006). Alternatively, the medium can be made selective for Pseudomonas spp. generally by the addition of Pseudomonas CFC Selective Supplement (LS0026). The presence of blue/green or brown pigmentation or fluorescence is indicative of presumptive Pseudomonas spp. It should be noted however that further testing must be carried out to confirm the full identity of the organism.
-
R2A agar is used for the enumeration and cultivation of bacteria from drinking water. R2A agar developed by Reasoner and Geldreich is a low nutrient medium that can used in pour plate, spread plate, and membrane filtration methods for heterotrophic plate counts. In combination with a lower incubation temperature and longer incubation period R2A agar stimulates the growth of stressed and chlorine-tolerant bacteria. Traditionally nutritionally rich media have been used for this purpose but these media support the growth of fast-growing bacteria and may suppress slow growing or stressed bacteria found in treated water. Enzymatic digest of casein, proteose peptone, acid hydrolysate of casein and yeast extract provide the required nitrogen, carbon and vitamins. Glucose is a fermentable carbohydrate. Dipotassium hydrogen phosphate is a buffering agent. Magnesium sulphate is a source of divalent cations and sulphate. Starch and sodium pyruvate aid in the recovery of stressed organisms.
-
This is a selective medium for the isolation of Salmonella spp. and Shigella spp. from clinical specimens and food samples. SS agar is a modification of the original DCA medium described by Leifson. The formulation for SS agar was later modified to improve the growth of Shigella spp. SS agar modified differs from SS agar in that it has an alternation to the bile salts mixture, peptone, pH value, and total g/litre. The peptone provides the required carbon, nitrogen and vitamins. Lactose is a fermentable carbohydrate and neutral red is a pH indicator. Sodium thiosulphate and ferric citrate are used to detect hydrogen sulphide production indicated by the black centred colonies of hydrogen sulphite positive organisms. Bile salts, sodium citrate and brilliant green inhibit Gram-positive bacteria and a number of different coliform bacteria.
-
Selenite cystine broth is a modification of selenite F broth and is for the selective enrichment of Salmonellae spp. from clinical, food and environmental specimens. The peptone acts as a nitrogen, carbon and vitamin source. Lactose is a fermentable carbohydrate and sodium phosphate is a buffer. L-cystine is used to enhance the recovery of Salmonellae spp. in low numbers. The medium is made selective by the addition of sodium biselenite (KM8021). Following overnight incubation subculture(s) are usually made on to one or more of the many selective enteric solid media.
-
This medium was originally described by Slanetz and Bartley(1) for the enumeration of enterococci from water samples using membrane filtration. The medium has also become useful as a direct plating medium. Tryptose and yeast extract provide the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate. The di-potassium hydrogen phosphate acts as a buffer. Selectivity is achieved through the addition of sodium azide which is used to suppress the growth of Gram-negative organisms. The medium contains tetrazolium chloride, which is reduced by enterococci to the insoluble red dye formazan resulting in dark red colonies of enterococci on the agar. It should be noted that this reaction is not exclusive to enterococci and colonies should be confirmed by additional testing e.g. aesculin hydrolysis.
-
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.
-
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.
-
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.
-
Tryptose is a mixed enzymatically digested protein. This product can be used in preparing microbiological culture media providing unique nutritional properties useful for cultivating fastidious microorganisms.
-
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
-
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
-
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
-
In vitro diagnostic. Dehydrated KM0179 Yersinia Selective Agar Base powder can be reconstituted to form a selective plated medium for the isolation and enumeration of Yersinia species from clinical and food samples.
