A computer-controlled microfluorometer with laser illumination: Study of lectin interaction with surfaces of human erythrocytes

Abstract

A fluorescence microscope based on a laser illumination and controlled by a computer is described. The instrumentation, its connection with the computer, and the developed FOR-TRAN programs are detailed. This semiautomatic system is easy to use and allows a cell-by-cell analysis of undisturbed cultured cells or of cell suspensions. An application to the study of fluorescent lectin interaction with plasma membranes of human erythrocytes is reported. For each sample the mean values and/or the distribution patterns of the detected fluorescence intensities are calculated or plotted. Thus, binding kinetics are obtained, showing that quantitation of site densities using a constant illuminated area is a valuable approach of the ligand-receptor interaction. The possibilities offered by a software extension are also mentioned.