FLUORESCENCE SATURATION IN CONFOCAL MICROSCOPY

The effects of fluorescence saturation on imaging in confocal microsco py have been studied. To include saturation it was necessary to deviat e from the widely assumed linear relationship between the fluorescence and the illumination intensity. The lateral response for a point-like object, as well as the optical sectioning power, decreases depending on the degree of saturation. For very high illumination intensities th e response for a saturated point object approached that of a conventio nal fluorescence microscope in which the fluorescence was not saturate d. The decrease in the axial confocal response has been confirmed qual itatively by experiment.