Indole Nitrate Broth is supplied by HiMedia. It is a sterile ready prepared media containing 5ml of light amber coloured clear solution in bottles. Indole Nitrate Broth is generally used for identification of microorganisms by means of nitrate reduction and indole production. It is advisable to store this ready prepared media between 2-8C. Composition (in gm/L) is as follows:

Tryptone (20.00)

Disodium phosphate (2.00)

Dextrose (1.00)

Potassium nitrate (1.00)

Agar (1.00)

Indole Nitrate Medium (Tryptone Nitrate Medium), supports growth of aerobes, microaerophiles, and facultative as well as obligate anaerobes owing to its nutritive content. It serves the dual purpose of detecting indole production as well as nitrate reduction in a wide range of microorganisms. Casein enzymic hydrolysate contains tryptophan, which is acted upon by certain microorganisms, resulting in the production of indole. Potassium nitrate acts as the substrate for determining nitrate reduction by microorganisms. Duplicate tubes of Indole Nitrate Medium may be inoculated and tested for the presence of nitrates or indole after incubation for various lengths of time.