Phalloidin is widely used in biological research for its ability to bind specifically to actin filaments in cells. This property makes it an essential tool for visualizing the cytoskeleton in fluorescence microscopy. By conjugating phalloidin with fluorescent dyes, researchers can stain and observe the intricate network of actin filaments in fixed cells, providing insights into cell structure, motility, and morphology. Additionally, it is utilized in studies of cellular processes such as endocytosis, cell division, and signal transduction, where actin dynamics play a critical role. Its high affinity and stability make it a reliable reagent for actin labeling in various experimental setups.