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 9689c5aa-6556-4b3c-b5d1-1e693715ba07's line of next-generation fluorescent dyes with advantages in brightness, photostability, and conjugate specificity compared to other fluorescent dyes. Orange fluorescent CF®543 dye has excitation/emission at 541/560 nm.