The PAS (periodic acid Schiff) reaction is one of the most frequently used chemical methods for histology. This Certistain Pararosaniline (chloride) solid dye is used to prepare the Schiff's reagent required for the PAS reaction, for the staining of mucopolysaccharides in histological tissue specimens.

Crystal violet or gentian violet, also known as methyl violet 10B or hexamethyl pararosaniline chloride, is a triarylmethane dye used as a histological stain and in Gram's method of classifying bacteria. Crystal violet has antibacterial, antifungal, and anthelmintic (vermicide) properties and was formerly important as a topical antiseptic.

Crystal violet is not only used as a textile dye, but also it is used to dye paper and as a component of navy blue and black inks for printing, ball-point pens, and inkjet printers. It is also used to colourize diverse products such as fertilizers, antifreezes, detergents, and leather.

PARAROSANILINE CHLORIDE FOR MICROSCOPY