CF® dye labeled dextrans could be used as a fluorescent fluid-phase markers to study cell permeability, endocytosis, or mechanisms of biomolecular delivery. The dextran conjugates are available in a variety of molecular weights, and contain a formaldehyde-fixable free-amine group. CF® dyes are Biotium's line of next-generation fluorescent dyes with advantages in brightness, photostability, and conjugate specificity compared to other fluorescent dyes. • Green fluorescent CF®488A dye has excitation/emission at 490/515 nm. • Orange fluorescent CF®543 dye has excitation/emission at 541/560 nm. • Orange-red fluorescent CF®555 dye has excitation/emission at 555/565 nm. • Red fluorescent CF®568 dye has excitation/emission at 562/583 nm. • Deep-red fluorescent CF®594 dye has excitation/emission at 593/614 nm. • Far-red fluorescent CF®640R dye has excitation/emission at 642/662 nm. • Far-red/near-IR fluorescent CF®680R dye has excitation/emission at 680/701 nm. • Near-IR fluorescent CF®680 dye has excitation/emission at 681/698 nm. • Near-infrared fluorescent CF®750 dye has excitation/emission at 755/777 nm. • Near-infrared fluorescent CF®770 dye has excitation/emission at 770/797 nm. • Near-infrared fluorescent CF®790 dye has excitation/emission at 784/806 nm. • UV-excitable blue fluorescent CF®350 dye has excitation/emission at 347/448 nm. • Far-red fluorescent CF®633 dye has excitation/emission at 630/650 nm.