Trypan Blue is widely used in biological and medical research as a vital stain to distinguish between live and dead cells. Its primary application is in cell viability assays, where it selectively colors dead cells with a distinctive blue hue, allowing researchers to assess cell health and count viable cells under a microscope. This is particularly useful in cell culture work, where monitoring cell survival and proliferation is essential. In tissue engineering, Trypan Blue is employed to evaluate the integrity of cell membranes during experiments, ensuring that only healthy cells are used for further studies or transplantation. It is also utilized in ophthalmology for staining the anterior capsule of the lens during cataract surgery, enhancing visibility and precision during the procedure. Additionally, Trypan Blue serves as a tool in microbiology to detect contamination in cell cultures, as it can identify non-viable microorganisms. Its simplicity and reliability make it a staple in laboratories for quick and effective cell viability assessments.