FLOW CYTOMETRIC MEASUREMENT OF NK CELL IMMUNOCONJUGATES BY PULSE-WIDTH PROCESSING

Pulse width analysis, in flow cytometry, has been widely used for opti mal cell size resolution in cell kinetics analysis, Pulses, generated by scattered light or fluorescence of cells, are electronically analyz ed for their height and width, The information generated from these tw o properties of the pulses is utilized to distinguish signals from sin gle cells vs, signals from cell clumps or aggregates, Pulse width, unl ike pulse height, is more sensitive to differences in cell diameter, a nd therefore can discriminate very small differences in it, which puls e height cannot, We have exploited this property of pulse widths to me asure immunoconjugates between NK cells and their targets, Discriminat ion of the free target cells hem the conjugated ones is possible by th e pulse widths of only light scatter signals, both forward and/or orth ogonal, This resolution was not obtained if pulse height of the same s ignals was visualized, Using this resolution it was possible to distin guish single cells from the aggregates between target and effector cel ls, We propose that this is a better method for distinguishing conjuga tes than the method in which prior vital staining of cells is used. (C ) 1995 Wiley-Liss, Inc.