Tinsdale Agar Base 500G

Tinsdale Agar Base with supplement is used for selective isolation and differentiation of Corynebacterium diphtheriae from diphtheroids. C. diphtheriae forms grayish black colonies surrounded by a dark brown halo while diphtheroids commonly found in the upper respiratory tract do not form such colonies. Dark brown halo around the colony is due to H2S production from cystinepresent in medium which combines with the tellurite salt.