• 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
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  • Dichloran Rose Bengal Chloramphenicol (DRBC) agar is based on the formulation described by King et al. and is used for the selective isolation and enumeration of yeasts and moulds from food samples. The peptone provides the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate. Potassium di-hydrogen phosphate is a buffering agent and magnesium sulfate is a source of divalent ions and sulfate. In order to curtail the size of the colony diameters of spreading fungi, the antifungal agent dichloran is added to the base and the pH is reduced to 5.6. Rose Bengal suppresses growth of bacteria and restricts the size and height of colonies of more rapidly growing molds. The inclusion of chloramphenicol ensures the suppression of bacteria present in environmental and food samples. Rose Bengal is absorbed by yeast and mold colonies and this further aids in their enumeration. Occasionally reduced recovery of yeasts may be encountered due to the increased activity of Rose Bengal at pH 5.6.
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  • 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.  
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  • 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.  
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  • Bacillus cereus (MYP) agar is intended for the selective enumeration of Bacillus cereus in food samples. This medium utilizes two reactions namely mannitol fermentation and lecithinase production to differentiate Bacillus cereus from other related species. As B. cereus is mannitol negative the colonies are pink in colour due to the presence of the phenol red pH indicator. Lecithinase production (from the addition of egg yolk) is indicated by a white precipitate around the colonies. This medium meets the requirements of ISO 7932:2004. Beef extract and peptone provide the required carbon, nitrogen and vitamins. Sodium chloride helps maintain the osmotic balance and phenol red is the pH indicator. Mannitol is a fermentable carbohydrate. The medium is made selective by the inclusion of polymyxin B sulphate (LS0020). NB: This is a basic medium only and contains no additional supplement. It should be noted that some Proteus spp. and Gram-positive cocci may grow on this medium. Related Supplements : LS0020 Bacillus cereus Selective Supplement, BM0140 Egg Yolk Emulsion
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  • Luria Bertani (LB) agar (Miller) is used for the cultivation and maintenance of recombinant strains of Escherichia coli and is based on the formulation stated by Miller. This medium is typically used in molecular biology procedures such as the detection of phage or plasmid transformed bacteria. LB agar (Miller) is prepared using 10 g/L of sodium chloride and this level varies from that described by Lennox. Enzymatic digest of casein provides the required nitrogen and carbon for organism growth. Vitamin B complex required by recombinant strains of E. coli are supplied by the yeast extract. Sodium chloride maintains the osmotic balance and provides sodium ions for membrane transport. Related Supplements : LS0035 Ampicillin Selective Supplement, LS0037 Kanamycin Selective Supplement
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  • LB agar (Lennox) is used for the cultivation and maintenance of recombinant strains of Escherichia coli and is based on the formulation stated by Lennox. This medium is typically used in molecular biology procedures such as the detection of phage or plasmid transformed bacteria. LB agar (Lennox) is prepared using 5 g/L of sodium chloride and this level varies from that described by Miller. This allows for additional sodium chloride to be added at the point of preparation if required. Enzymatic digest of casein provides the required nitrogen and carbon for organism growth. Vitamin B complex required by recombinant strains of E. coli are supplied by the yeast extract. Sodium chloride maintains the osmotic balance and provides sodium ions for membrane transport. Related Supplements : LS0035 Ampicillin Selective Supplement, LS0037 Kanamycin Selective Supplement
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  • 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.  
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