Phalloidin-iFluor® 514 Conjugate

This yellow fluorescent phalloidin conjugate (equivalent to Alexa Fluor® 514-labeled phalloidin) selectively binds to F-actins. Phalloidin derivatives are convenient probes used at nanomolar concentrations for labeling, identifying, and quantitating F-actins in formaldehyde-fixed and permeabilized tissue sections, cell cultures, or cell-free experiments. Phalloidin binds to actin filaments much more tightly than to actin monomers, leading to a decrease in the rate constant for the dissociation of actin subunits from filament ends, essentially stabilizing actin filaments through the prevention of filament depolymerization. Moreover, phalloidin is found to inhibit the ATP hydrolysis activity of F-actin. Phalloidin functions differently at various concentrations in cells. When introduced into the cytoplasm at low concentrations, phalloidin recruits the less polymerized forms of cytoplasmic actin and filamin into stable "islands" of aggregated actin polymers. Yet, it does not interfere with stress fibers, i.e., thick bundles of microfilaments. The property of phalloidin is a valuable tool for investigating the distribution of F-actin in cells by labeling phalloidin with fluorescent analogs and using them to stain actin filaments for light microscopy. Fluorescent derivatives of phalloidin have been enormously helpful in localizing actin filaments in living or fixed cells and visualizing individual actin filaments in vitro. Fluorescent phalloidin derivatives have been used as an important tool in studying actin networks at high resolution. AAT Bioquest offers a variety of fluorescent phalloidin derivatives with different colors for multicolor imaging applications.