Monochlorobimane is widely used in biological research as a fluorescent probe for detecting and measuring glutathione levels in cells. It specifically reacts with glutathione to form a highly fluorescent adduct, allowing researchers to visualize and quantify glutathione in live cells and tissues. This application is particularly useful in studies related to oxidative stress, cellular detoxification, and redox biology. Additionally, it is employed in flow cytometry and fluorescence microscopy to assess glutathione distribution and dynamics in various cell types. Its sensitivity and specificity make it a valuable tool for understanding cellular responses to environmental and pharmacological challenges.