Streptavidin conjugates are high quality streptavidin biotin binding protein labeled with CF® dyes and a selection of other labels. CF® dyes are Biotium's line of next-generation fluorescent dyes with advantages in brightness, photostability, and conjugate specificity compared to other fluorescent dyes. 405 nm-excitable green fluorescent CF®440 dye has excitation/emission at 440/515 nm.