Merck

Gram Crystal Violet solution 500ml is a basic dye used in microbiology, mainly for Gram staining. It is a triarylmethane dye, which binds to the cell walls of bacteria, allowing them to be differentiated into Gram-positive and Gram-negative. During the Gram staining process, Crystal Violet penetrates the cells and forms a complex with iodine (using Gram Iodine solution). Gram-positive bacteria, due to the thicker peptidoglycan layer in their cell wall, retain the dye and remain purple after washing with alcohol. In contrast, Gram-negative bacteria are decolorized and then stained pink using a counterstain (usually safranin). Gram Crystal Violet is essential in clinical and research laboratories, as it allows for the rapid and reliable identification of bacterial infections, contributing to diagnosis and the selection of appropriate treatment. In addition to Gram staining, it can also be used in other microbiological and histological applications.