A CHEMICALLY SPECIFIC DOUBLE-STAINING TECHNIQUE FOR DESOXYRIBOSENUCLEIC ACID AND OTHER ALDEHYDE-YIELDING OR ALDEHYDE-CONTAINING SUBSTANCES

A chemically specific double staining procedure has been devised for Chlamydomonas, which depends upon the staining of the phosphoric acid moiety of the chromosomal DNA in hydrochloric acid hydrolyzed cells, with the subsequent transfer of the basic dye (azure A) to the aldehyde radicals of the DNA in the presence of sulfurous acid. Subsequent treatment with Schiff reagent stains the primary zygote membrane magenta by combining with its free aldehyde groups. The method as outlined is simple and useful with potentials for application to other types of cells.