ANALYSIS OF LYMPHOCYTE-ACTIVATION AND PROLIFERATION BY VIDEO MICROSCOPY AND DIGITAL IMAGING

Video microscopy and digital imaging were used as a noninvasive method to quantitatively analyze lymphocyte activation and proliferation. Th is method takes advantage of the fact that upon activation lymphocytes blast and become significantly larger before proliferating. The mean cell sizes of T lymphocytes in an activation kinetics assay were measu red by digital image analysis and compared to [H-3]-thymidine incorpor ation of cells under the same treatment. An increase in cell size was observed before [H-3]-thymidine incorporation; therefore the digital i maging assay is more sensitive in determining the earliest time-point of activation. Also, the digital imaging assay was comparable to the [ H-3]-thymidine incorporation assay in providing information about the extent and rates of T lymphocyte proliferation. Cellular DNA was stain ed with propidium iodide to show that the larger blasting cells in the population of activated T lymphocytes were indeed the cells that acco unted for the increase in DNA synthesis and thus an increase in cell s ize can be correlated with activation. (C) 1993 Wiley-Liss, Inc.