[Possibilities and limits of the quantitative demonstration of protein thiols with the DDD-reagent in cells of cervical epithelium (author's transl)].

From six patients, all with invasive carcinoma of the cervix uteri, two groups fo smear preparations, each consisting of eight samples, were taken: The first, group A, before and the second, group B, after mechanical removal of the discharge which was present in abundant quantities. All samples were treated for 24 h with DDD to reach the fast-reaching SH-groups, coupled with Fast Blue B and measured cytophotometrically at 560 nm. Without any exception, the neoplastic cells of group A showed significantly lower extinction values both of the nucleus and of the total cell, if compared to group B. The mean extinction difference amounts to 55% and is highly significant and some evidence is given that the viability of the cells plays an important role. For this reason, the quantitative evaluation of the DDD Fast Blue B does not seem to be useful for cytologic routine investigations.