MTS-CF594 is a fast-reacting and highly selective thiol-reactive label that permits one to attach CF594 to a thiol group. CF594 is spectrally similar to Alexa Fluor? 594 and Texas Red? dye but yields much brighter protein conjugates due to its high quantum yield and exceptional water solubility. CF594 also has excellent photostability ideal for demanding applications, such as confocal microscopy and single molecule imaging. The dye is particularly useful to combine with our blue fluorescent CF350, green fluorescent CF488A and far red CF633 or CF647 for multi-color imaging.