[Chromatin staining with thallium in NK/Ly ascites tumors of various ages]

Staining of the chromatin in the NK/Ly ascitic tumour was studied by electron microscopy using Mentré's thallium method. Investigations were carried out on the 2., 7., 9., and 14th days after the transplantation of the tumour. It was established, that the chromatin of the nuclei of the proliferating--2 days old--tumour cells occurs in dispers form. Later the temp of the growth decreases and as the consequence of the aggregation of the chromatin electrodense areas are formed. Authors assume, that on the base of the morphological alterations transformation of diffuse chromatin into aggregated one depression of the gene-substance might lie.