Photothermal image cytometry of human neutrophils.

Photothermal imaging, when applied to the study of living cells, provides morphofunctional information about cell populations. In technical terms, the method is complementary to optical microscopy. The photothermal method was used for cell imaging and quantitative studies. We have developed a dual-laser technique and have constructed an automated image cytometer based on an optical microscope. The theory of the method, the technical equipment, and the computer software are described. With our technique, three types of cell images can be acquired and analyzed: optical, pulsed laser time-domain, and photothermal. The parameters of each kind of image are considered in detail. Preliminary results of studies on living human neutrophils are presented.