Cytofluorometric study of thiol and disulphide groups in guinea pig epidermis.

Content of thiol and disulphide groups was cytofluorometrically measured on guinea pig keratinocytes, which were separated into three fractions. Free keratinocytes were obtained by the treatment of EDTA and trypsin. After the treatment keratinocytes were separated into three fractions by centrifugation on a continuous colloidal silica (Percoll) density gradient. Cells in each fraction were stained with N-(7-dimethylamino-4-methyl-3-coumarinyl)maleimide, and measured by cytofluorometry. Thiol concentration was low in basal cells, and higher in both spinous and granular cells. Disulphide group content was low and fairly constant in them. Human peripheral lymphocytes and guinea pig spleen lymphocytes were used to examine the influence of EDTA-trypsin treatment. No remarkable loss of either thiol or disulphide groups was found in them after the treatment.