Microphotometrical quantification of protein thiols in morphologically intact cells of the cervical epithelium. I. Basic results with superficial cells of healthy women.

The investigations are based on Esterbauer's results according to which the staining of protein thiols (PSH) with DDD-Fast Blue B (Barrnett and Seligman) is of a quantitative order. Consequently, the PSH of the nucleus and the cytoplasm of superficial cells of the ectocervical epithelium of healthy women are determined to 0.3 and 4.1 X 10(-14) moles, respectively. After it has been found that the mean absorption spectrum between 310 and 238 nm of the pure proteins, the extinction at 278 nm of a cytoplasmic area (300 to 400 micron2) of unstained cells is taken as a first measure for the cytoplasmic protein content which is calculated to approximately 5 X 10(-18) moles per micron2 whereas the PSH content results to 1.9 X 10(-17) moles per micron2. From this value results a very plausible number of 3.6 SH per 10(5) g of cytoplasmic proteins.