50738 GN Enrichment Broth, Merck

GN (Gram-Negative) Broth was originally developed by Hajna as a superior enrichment medium for the recovery of Shigella and Salmonella. It is specifically formulated to favor the growth of these pathogens while temporarily suppressing the growth of coliforms and other enteric bacteria (like Escherichia coli and Proteus). The selectivity is achieved through the use of sodium citrate and sodium deoxycholate. The medium contains a higher concentration of mannitol than glucose to further encourage the growth of Salmonella and Shigella over other enteric organisms. As part of the NutriSelect® Plus line, this medium ensures premium quality and performance for diagnostic and industrial applications.

Advantages

• Optimized for Shigella: One of the most effective enrichment broths for the recovery of fastidious Shigella species.
• Short Enrichment Time: Designed for a rapid 6-to-8-hour enrichment period, allowing for subculturing on the same day.
• High Selectivity: Effective inhibition of Gram-positive organisms and early suppression of common Gram-negative commensals.
• NutriSelect® Plus Quality: Rigorous quality control ensures high recovery rates and consistent biochemical properties.
• Balanced Nutrients: A combination of glucose and mannitol provides versatile energy sources for target enteric pathogens.

Interpretation of Results

After the enrichment period, the broth should show turbidity indicating microbial growth. Since this is an enrichment medium, it is not intended for definitive identification. Subculturing on selective media is required to isolate and identify the specific pathogens recovered.

Technical specifications

Available packaging options