MTS CF® Dyes have a fast-reacting and highly selective thiol-reactive methanethiosulfonate (MTS) group, that allows CF® dyes to be conjugated to thiols. CF® dyes are Biotium's line of next-generation fluorescent dyes with advantages in brightness, photostability, and conjugate specificity compared to other fluorescent dyes. • Far-red fluorescent CF®640R dye has excitation/emission at 642/662 nm. • Green fluorescent CF®488A dye has excitation/emission at 490/515 nm. • Orange fluorescent CF®543 dye has excitation/emission at 541/560 nm. • Deep-red fluorescent CF®594 dye has excitation/emission at 593/614 nm.