Simultaneous measurement of five-cell surface antigens by five-colour immunofluorescence.

Multicolour immunofluorescence and flow cytometry were used for simultaneous measurement of five-cell surface antigens on murine spleen cells. We have been able to quantitate T-cells, T-cell subsets, B cells, and expression of the activation marker I-Ad from a single sample using four directly conjugated monoclonal antibodies LYT2-APC, L3T4-PE, B220-RED613, I-Ad-FITC and one indirect step THY1.2-biotin/streptavidin-Cascade Blue. Three excitation wavelengths were used (488 nm, 647 nm, and U.V. 351-364 nm) for fluorescence measurements. The combination of fluorochromes used provided good resolution such that all five fluorescence signals were spectrally resolved. The percentage of cells positive for expression of a specific cell surface marker were almost identical for single-colour samples and the five-colour analysis, differing by only 0.3-1.5 percentage points.