OBSERVATION OF SINGLE-CELL FLUORESCENCE-SPECTRA IN LASER FLOW-CYTOMETRY

We report the first demonstration of directly recording fluorescence s pectra of single cells in now cytometry, An intensified, 512-element p hotodiode array was used in conjunction with a dispersing prism to cap ture the fluorescence emission spectra of Coulter ImmunoCheck calibrat ion beads and Dictyostelium discoideum spores stained with the indocar bocyanine derivative CY3, fluorescein isothiocyanate, or R-phycoerythr in. The demonstration was made feasible by enhancing the signal-to-noi se ratio of the detection process by using a fast gating technique app lied to the detector, Results show that the complete fluorescence spec tra of individual stained cells contain information that is normally n ot captured by conventional now cytometers. By using the spectrographi c now cytometer, all this information is recorded, allowing small feat ures and shifts in the fluorescence spectra of labelled particles to b e studied. (C) 1996 Wiley-Liss, Inc.