Aniline Blue water soluble is widely used in biological staining, particularly in histology and microbiology. It serves as a counterstain in combination with other dyes to differentiate cellular structures under the microscope. It is commonly used in the identification of fungal elements in tissue sections due to its affinity for fungal cell walls. In some staining protocols, it highlights collagen fibers, aiding in the assessment of connective tissue disorders. It is also employed in textile industries for dyeing wool and silk, providing a bright blue color with good fastness properties. Additionally, it finds use in ink formulations and as a pH indicator in certain analytical applications.