Abstract
The dependence of the turbidity in yeast suspensions treated with various amounts of cetyltrimethylammonium bromide (CTAB) on the percentage of killed cells provides a means for the determination of the germicidal effect. Empirical equations which describe the observed relationship between turbidity and mortality were derived, and turbidity measurements necessary to estimate the killed fractions of the sample were described. The time course of the germicidal action of CTAB upon yeast cells was observed by using this method. The turbidity change thereby observed can be accounted for by the change in cell volume resulting from the cell degeneration. Some observations on different microbes treated with various germicides suggest that the present method may be applicable to other kinds of germicides and microbes.
