Crystal violet is widely used as a biological stain in microbiology and histology. It is a key component in the Gram staining procedure, which differentiates bacteria into Gram-positive and Gram-negative groups based on their cell wall properties. This helps in identifying and classifying bacterial species in clinical and research settings.

In addition to its staining applications, crystal violet is utilized in the textile industry as a dye for coloring fabrics, particularly silk and paper. It provides a deep purple hue and is valued for its colorfastness.

The compound also finds use in veterinary medicine as an antiseptic and antifungal agent. It is applied topically to treat minor skin infections, wounds, and fungal infections in animals.

Furthermore, crystal violet is employed in water treatment processes to inhibit the growth of algae and bacteria in cooling towers and industrial water systems. Its antimicrobial properties help maintain water quality and prevent biofouling.

In research, crystal violet is used as a pH indicator, changing color in response to variations in acidity or alkalinity. This makes it useful in laboratory experiments and chemical analyses. It is also employed in cell proliferation assays to study the growth of cells and tissues.

However, crystal violet should be used with caution due to potential environmental and health impacts.