Tryptic Soy Broth without Dextrose is an enzymatic digest of casein and soybean meal. It is a low carbohydrate basal medium used for cultivating fastidious and nonfastidious microorganisms. Dextrose is omitted from the formula to permit use of the medium in fermentation studies where carbohydrates may be added. The carbohydrate concentration used most frequently in fermentation reactions is 0.5% or 1%.