GranuCult^® plus Eosin Methylene Blue Agar

GranuCult^® plus EMB Agar acc. HOLT-HARRIS and TEAGUE is a low selective and differential medium containing lactose and sucrose and two indicator dyes, Eosin and Methylene Blue. The use of these two indicators allows differentiation between colonies of lactose and/or sucrose fermenting and non-fermenting organisms. Sucrose is included since certain members of the coliform group of microorganism ferment sucrose more readily than lactose. This formulation does not discriminate between carbohydrate utilization (lactose or sucrose).
The peptones provide nitrogen, minerals and amino acids, lactose and sucrose provide the carbon sources. Di-potassium phosphate acts as a buffer whilst Eosin yellowish (Eosin Y) and methylene blue serve as differential indicators and inhibitors. Agar is the solidifying agent.
Coliforms produce blue-black colonies due to the incorporation of an eosin-methylene blue dye complex when the pH drops down. Colonies of Escherichia coli may show a characteristic green metallic luster due to the rapid fermentation of lactose. Lactose- and sucrose-non fermenting bacteria (like most Salmonella and Shigella) will form colourless or transparent amber-coloured colonies, but some strains of Salmonella and Shigella may not grow on this culture medium. Some Gram-positive bacteria and yeasts may grow on this culture medium and usually form pinpoint colonies.

GranuCult^® plus Eosin Methylene Blue Agar is a low selective, differential agar used to identify coliforms especially E. coli. It differentiates lactose fermenters from non-lactose fermenters.It is often the media used when testing the potability of water via the MPN method

GRANUCULT is a registered trademark of Merck KGaA, Darmstadt, Germany

NutriSelect is a registered trademark of Merck KGaA, Darmstadt, Germany

We offer two media types: the superior granulated GranuCult^® and the cost-efficient powdered NutriSelect^® culture media, depending on your needs. The designations basic, plus, or prime are added to indicate the quality control level, from basic quality control to standard QC plus to prime for full regulatory compliance.