[Single cell fluorescence photometry for quantification of antigens on alveolar macrophages]

The quantitation of cell surface antigens on alveolar macrophages (AM) using flow-cytometry is complicated by strong autofluorescence and wide variation of cell- size and autofluorescence. Therefore a microscope-fluorometric method was developed which allows simultaneous assessment of fluorescence of fluorochrome-labelled monoclonal antibodies and size in individual cells. Autofluorescence of smokers AM was found to be variable and considerably stronger than autofluorescence of nonsmokers AM. By means of a multi step determination of autofluorescence and specific fluorescence using different filter combinations of the microscope fluorometer density of membrane bound HLADR-antigens could be efficiently determined also in strongly autofluorescent smoker AM.