Flow cytometric analysis of immunogold cell surface label.

Goat antimouse immunoglobulin antibodies conjugated to colloidal 40-nm gold particles were used to label mouse spleen lymphocytes. The labeled cells were analysed with a flow cytometer, equipped with an argon-ion laser and a (0.5 mW) helium-neon laser. The right-angle (90 degrees) light scatter signal of the red (632.8 nm) helium-neon light was enhanced more than tenfold by the gold label. Dual labeling with gold and fluorescein isothiocyanate (FITC) showed no interference between the two labels. Thus immunogold provides a nonfluorescent cell surface label that can be combined with other cell labels for multiparametrical cell analysis.