Abstract
SUMMARY: When viewed in the electron microscope, cells of Staphylococcus aureus, Streptococcus faecalis and Escherichia coli changed markedly when suspended in cetyltrimethylammonium bromide (CTAB) solutions instead of distilled water; the cytoplasm contracts away from the cell wall. The proportion of cells showing such contraction, in the case of Esch. coli, can he correlated with the proportion of cells killed by the treatment. High concentrations of CTAB appear to strip off the cell envelopes.