Automatic fluorescence microphotometer using an image dissector tube

Abstract

An automatic fluorescence microphotometer using an image dissector tube as the fluorescence detector is described. The image dissector tube is used in the photon-counting mode of operation to allow precise intensity measurements of weak fluorescent spots. With the support of a laboratory-built microcomputer system, the instrument can automatically search for cells stained with fluorescent dye in the microscope field; then the detected cells are individually put in the measuring probe region to have their fluorescence intensities measured. Finally a fluorescence distribution histogram of stained cells is automatically generated and graphically presented. The instrument also allows a fluorescence intensity mapping operation utilizing the conventional raster scanning technique. To demonstrate the system’s performance, DNA in rat liver nuclei stained with Feulgen dye was measured.