Aniline Blue (spirit soluble) is widely used in biological and histological staining. It is particularly effective in differentiating tissues under microscopic examination, aiding in the visualization of cellular structures. In botanical studies, it is employed to stain plant tissues, helping researchers analyze cell walls and other components. Additionally, it is used in microbiology to enhance the contrast of bacterial samples, making it easier to study their morphology. Its solubility in alcohol makes it a preferred choice for specific staining protocols that require organic solvents.