Fluorescent stains are special dyes that emit light when exposed to specific wavelengths of light, usually ultraviolet (UV) or blue light. These stains are commonly used in biological and medical research to highlight and visualize structures within cells and tissues. By binding to specific cellular components, such as proteins or nucleic acids, they allow scientists to observe and study cellular processes in detail. In microscopy, fluorescent stains enhance the contrast of samples, making it easier to identify and analyze different cellular structures. Techniques like fluorescence microscopy utilize these stains to provide insights into cellular functions, disease mechanisms, and the effects of treatments, contributing significantly to fields like cell biology and pathology.