Abstract

The traditional domain of flow cytometry has been the measurement of properties of discrete biological particles - primarily cells or chromosomes. Most flow cytometric fluorescence measurements of cell properties are determinations of the amount of a specific type of molecule in a cell, such as DNA or a cell surface antigen. Since the inception of flow cytometry, there has been a continuing guest for more sensitive instruments and for techniques to detect and quantitate low levels of fluorescence. A generally accepted value for the sensitivity of detection of fluorescein on the surface of a cell is 3 000 to 5 000 molecules.

© 1987 Optical Society of America