Near-IR dyes in three-color volumetric capillary cytometry: cell analysis with 633- and 785-nm laser excitation.

Several fluorescent dyes that absorb in the near-infrared are described. The photostability and aggregation properties of the dyes were examined. Two of the dyes, BHMP and BHDMAP, emit at 805 nm and were useful dyes for protein labeling. A dual-laser, three-color scanning instrument was constructed. CD3+CD4+ and CD3+CD8+ populations were enumerated in undiluted, whole blood based on the fluorescence of Cy5, Cy5.5 and BHMP.