Hofman's Violet

Hoffman's violet is specific stains for animal chromosomes. Iodinated alcohol after staining can be substituted with various acids, both organic as well as inorganic, all of which act as trapping agent preventing leaching of the dye that binds with the chromosomal DNA. RNA is not involved by this process of staining, since treatment of stained sections with cold phosphoric acid at 5 degrees C for 20--25 min and then stained also reveals perfect colouration of the chromosomes without any cytoplasmic staining.