DIAGNOSTIC THIOGLYCOLLATE MEDIUM W/O INDICATOR

Description

Thioglycollate Medium without Indicator is a semisolid medium originally formulated by Brewer for the growth of aerobic and anaerobic microorganisms. Previously methylene blue was incorporated in the medium as an Eh indicator but has been omitted now to enable recognition of early growth and avoids any toxic effects of indicator. This medium supports a minimal inoculum with early visibility of growth. Obligate aerobes grow at the top of the medium, while anaerobes grow at the bottom of the medium. This medium is nutritious and favours the growth of Clostridium butyricum, Campylobacter species, Bacteroides species and Pneumococci etc. from minimal inocula. Brucella species which fail to grow in the presence of indicator, can grow in this medium. The broth with addition of 10% v/v serum may be used for cultivation of Trichomonas vaginalis. It can also be used as transportation medium for which calcium carbonate is incorporated in the medium. Calcium carbonate neutralizes the acid produced during growth and avoid rapid growth and death of gram-negative cocci, Clostridium perfringens and other acid-sensitive bacteria.