ABSTRACT
Procedures were worked out for evaluating the most common stains by Peterson et al. (1933a,b,c; 1934a,b). These methods, improved and extended over the years, are used in the examination of dyes submitted to the Biological Stain Commission for certification. In addition to determining the dye content, stains are tested in the applications for which they are supplied, and some are tested for purity by examination of the complete absorption spectrum and by chromatographic methods.
