Factors involved in the production of banded structures in mammalian chromosomes

Dozens of reagents were tested for their ability to produce bands in Chinese hamster chromosomes by incubating air-dried preparations in aqueous solutions of these reagents for a definite period prior to the Giemsa staining. Acids were found to be without effect on the band production. Many of salts were able to induce bands if their pH was alkaline. Strong bases were also found to be potent band inducing reagents. They produced bands only in a few seconds. Protein denaturants such as urea, guanidine-HCl and several surface active compounds were also effective in the band production. — In the light of these results, it seems very likely that the solubilization or extraction of some chromosomal proteins, probably of acid nature, would be the primary cause of the appearance of the banded structure in chromosome arms.Contribution No. 885 from the National Institute of Genetics, Japan.