Histophotometric quantification of protein and reactive proteinthiols in invasive carcinomas of the skin.

Frozen sections cut from 14 samples of invasive carcinomas of the skin were stained with Amido black for protein determination and with dihydroxydinaphthyldisulphide fast blue to quantify reactive protein thiols (PSHr) and were then analysed microphotometrically. It was found that all of the samples exhibited significant reductions in protein levels (49%-74%) and PSHr levels (32%-53%) as compared to normal epidermis. Thus, the content of proteins of PSHr groups was 1.7 times greater in the malignant tissue examined than in normal epidermis. These results are in accordance with those previously obtained in basal-cell epitheliomas.