Histochemical determination of histone and non-histone protein content in rat liver nuclei.

The purpose of this study is to compare the protein content of parenchymal and non-parenchymal nuclei, as isolated from rat liver. The nuclei have been separated by means of a 1 g-sedimentation technique. The protein content of the separated nuclei has been determined cytophotometrically using the Naphthol Yellow S staining procedure after TCA-extraction (corresponding with the total protein content) and directly (corresponding with the non-histone proteins). The ratio of the total protein content of non-parenchymal, parenchymal diploid and parenchymal tetraploid nuclei respectively was found to be 0.65:100:1.90. The ratio of non-histone protein a total protein was the same for all types of nuclei investigated, namely about 55%.