62087 Levine EMB Agar, Merck

Levine EMB Agar (NutriSelect® Basic) is formulated according to the modification developed by Levine, which differs from the Holt-Harris and Teague formula by the omission of sucrose and a change in the ratio of the dyes. The medium uses Eosin Y and Methylene Blue as both selective agents (inhibiting Gram-positive bacteria) and pH indicators. When lactose is fermented, the acid produced causes the dyes to precipitate, giving the colonies a deep purple color or a characteristic metallic sheen. This medium is highly effective for the presumptive identification of Escherichia coli and is widely used in the testing of water, dairy products, and clinical samples.

Advantages

• Presumptive ID: Provides the iconic metallic green sheen for the rapid identification of E. coli.
• NutriSelect® Basic Quality: A reliable, cost-effective choice for routine microbiological screening and laboratory use.
• Standardized Differentiation: Effectively separates coliforms into those that ferment lactose rapidly (e.g., E. coli) and those that ferment it slowly (e.g., Klebsiella).
• Selective Properties: The dye combination ensures the suppression of most Gram-positive contaminants while remaining gentle enough for fastidious Gram-negative rods.
• Clear Visual Results: High contrast between fermenting (dark/sheen) and non-fermenting (colorless) colonies.

Interpretation of Results

Technical specifications

Available packaging options