Histochemical Studies on Chromosomes

Abstract

1. Histochemical tests in regard to glycogen were successful on the salivary gland chromosomes. The existence of glycogen seems to be specifically found only in the salivary gland chromosomes of the Diptera, and the fact that the glycogen in chromosomes is uniformly stained makes the authors feel that glycogen must be located in matrix.
2. It was demonstrated in detail from the standpoint of microchemical reaction as well as isoelectric point of chromosome that the protein of the salivary gland chromosomes is at most only partially digested by pepsin, , though completely digested by trypsin.
3. It was revealed an interesting metachromasia that the chromosome aquired a reddish purple by staining with toluidin blue which was at more alkalic side than pH 4.4 in pepsin digestion, and at more alkalic side than pH 1.8 in trypsin digestion.
4. It was confirmed that the metachromasia of toluidin blue in chromosome depends upon the existence of desoxyribose-nucleic acid uncompounded with protein.
5. The kind of basic protein of the salivary gland chromosomes was decided by staining with brillantazurin B as well as isoelectric point to prove that the greater part of the basic protein was histone, a part of it being a non-histone protein.