BacterTube™ GN Broth

INTENDED USE

BacterTube™ GN Broth is a selective enrichment medium for isolating Salmonella and Shigella from clinical and non-clinical specimens, including stool, urine, and food samples. It is also recommended by APHA for food microbiological examinations.

PRINCIPLES

GN Broth contains:
- Tryptose: Provides amino acids and nitrogenous substances for bacterial growth.
- Sodium citrate and sodium deoxycholate: Inhibit Gram-positive organisms and some coliforms.
- Mannitol (higher concentration than dextrose): Limits Proteus growth while promoting mannitol-fermenting Salmonella and Shigella.
- Phosphates: Act as buffers to maintain pH stability.
- Sodium chloride: Ensures osmotic equilibrium.
The medium supports the enrichment of Salmonella and Shigella, even when present in low numbers, making it ideal for rectal swabs, fecal samples, and food testing.

Use the medium directly with the specimen. For stool samples, inoculate approximately 1 gram.
Incubate the inoculated broth at 35 – 37°C for 6 – 8 hours.
Perform sub-culturing onto selective agar after 6 – 8 hours and again after 24 hours

BacterLab ensures the quality of each product batch by testing with ATCC reference strains.

Reference strains	Incubation conditions	Expected results
Escherichia coli ATCC 25922	18 – 24 hours, 33 – 37°C	Inhibited, no growth
Salmonella Typhimurium ATCC 14028		Good growth
Shigella sonnei ATCC 9290		Good growth

For 1 liter of medium

pH of the ready-to-use medium at 25°C: 7,0 ± 0,2

*Note: This ingredient is for reference only our company will formulate the ingredient according to requests or tender specifications.

Product Name	Code	Packaging
BacterTube™ GN Broth	08007	50 tubes/ box or as per customer request.