Ethidium bromide is widely used in molecular biology for visualizing nucleic acids. It is commonly applied in agarose gel electrophoresis to stain DNA and RNA, allowing researchers to observe and analyze the size and quantity of nucleic acid fragments under ultraviolet light. Due to its ability to intercalate into double-stranded DNA, it fluoresces brightly, making it a valuable tool for detecting DNA bands. However, its use requires careful handling due to its mutagenic properties, and it is often replaced by safer alternatives in modern laboratories. Additionally, it has been utilized in studies of DNA structure and function, as well as in fluorescence-based assays to investigate nucleic acid interactions.