Rhodamine B isothiocyanate (RITC) is a cell-permeant fluorogenic dye most often used as a conjugate to antibodies and proteins for fluorescence detection in microscopy. It displays excitation/emission maxima of 570/595 nm, respectively, and can be used in conjunction with immunohistochemistry for multi-labeling studies. It has also been used as an anterograde and retrograde tracer in neurons and in nanoparticles to detect apoptosis.