Abstract
Summary The effect of various concentrations of sodium thioglycollate (0–0·05 %) on the recovery of spores of four strains of clostridia was investigated. The results showed that thioglycollate at a concentration of 0·01 % can be inhibitory to some clostridia. However, the results also indicated that the inhibitory effect is dependent upon the composition of the growth medium. The presence of glucose appeared to be particularly important in reducing the inhibitory effect. These findings support the view that the use of sodium thioglycollate in sterility test media should be discontinued.