-
Chocolate Agar with 7% Horse Blood & Bacitacin A highly nutritious medium enriched with Horse Blood, where the blood has been ‘chocolated’ by heating the medium to 70°C. Suitable for the isolation of most pathogens including many fastidious organisms the addition of Bacitracin makes it is particularly suitable for the selective isolation of Haemophilus spp. -
CLED Agar Mackey and Sandy’s formulation this medium is popular for Urine Culture in the clinical laboratory. The lack of electrolytes inhibits the spreading of Proteus spp. and Bromothymol Blue indicator allows easy differentiation of Lactose and Non-Lactose fermenting organisms. Cystine is also present to benefit those organisms that have a particular Cystine requirement. Streptococcus pyogenes and many other fastidious organisms that do not require the presence of blood can grow on this medium. -
A general purpose medium enriched with 5% Defibrinated Horse Blood, suitable for the isolation of most organisms including many fastidious anaerobes. -
DN'ase Medium DNase Agar is used primarily in clinical laboratories to differentiate Staphylococcus aureus from other Staphylococci based on deoxyribonuclease activity. Following incubation of the plate and confirmation of a pure growth of Staphylococci, the surface of the medium is covered with a small quantity of 1M Hydrochloric Acid to precipitate the DNA. Staphylococcus aureus produce DNase enzymes that hydrolyse DNA resulting in a clear area around the colonies, described as being DNase positive, whereas coagulase negative Staphylococci do 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. -
Mueller Hinton Agar is recommended for use in the antibiotic disk diffusion method by both the European Committee on Antibiotic Sensitivity Testing (EUCAST) and the Clinical Laboratory Standards Institute (CLSI). The medium contains low levels of divalent metal cations, such as calcium and magnesium, to minimise any interference with certain antibiotic classes e.g. aminoglycosides. Starch is also present to absorb any toxic metabolites that may be formed during growth. The medium is low in thymine & thymidine content and is therefore suitable for use in testing sulphonamides and trimethoprim without the addition of blood. -
Mueller-Hinton Agar is a defined medium used primarily in Antimicrobial Sensitivity Testing using the disc diffusion technique described by Bauer-Kirby. It has been approved as the definitive medium for this purpose by the European Committee on Anitmicrobial Susceptibility Testing (EUCAST). This medium contains low levels of thymidine and thymine and controlled levels of calcium and magnesium ions. Additional supplementation of the Mueller Hinton medium using 5% Horse Blood and 20mg/L of Nicotinamide adenine dinucleotide (NAD) makes it suitable for use with the more fastidious organisms such as Streptococcus pneumoniae and Haemophilus influenzae. -
This is a chromogenic medium based on CLED that has been developed to allow differentiation and presumptive identification of organisms typically found in urinary tract infections. Reduced electrolyte concentration prevents swarming of Proteus spp. A sophisticated binary chromogenic system and supplementation with tryptophan allows differentiation of Enterococcus spp. (turquoise colonies), Proteus spp. (clear colonies with a brown halo), Enterobacter spp. (metallic blue colonies), Staphylococcus spp. (white colonies), and E. coli (purple colonies).
