CHANGES IN THE STAINING CAPACITY OF NUCLEAR COMPONENTS DURING CELL DEGENERATION

Abstract

1. Quantitative changes in the staining capacity of nuclear DNA and basic proteins during pycnosis of guinea pig follicle cells were investigated by photometric techniques. The great density of these pycnotic nuclei requires special precautions during photometric analysis.2. The results show that amounts of measurable DNA, in terms of Feulgen dye, decrease during pycnosis, probably because of progressive nuclear fragmentation. At the same time the methyl green basophilia, per unit Feulgen-DNA, is greatly enhanced. Basic proteins show an even greater relative increase in their capacity to bind acid dye during pycnotic degeneration.3. These data are interpreted to indicate that a dissociation of the normal nucleoprotein complexes occurs during the degenerative process; this leads to unmasking of charged groups which had previously been unavailable for combination with dye ions.4. The pattern of pycnosis in the present material appears to differ from that previously described for tumor nuclei.