Used primarily in biological and medical research to distinguish between live and dead cells in a sample. It is a vital stain that helps in assessing cell viability, as it selectively colors dead cells blue, while live cells remain unstained. Commonly applied in cell culture experiments, tissue engineering, and microbiology to evaluate the health of cell populations. It is also utilized in ophthalmic surgeries to stain the anterior capsule of the lens, enhancing visibility during procedures like cataract extraction. Its application extends to histology for differentiating tissues and identifying damaged areas in biological specimens.