A FLOW CYTOMETRIC METHOD TO MEASURE SHAPE CHANGE OF HUMAN NEUTROPHILS

1. We report a flow cytometric method in which changes in forward angl e light scatter are shown to correlate with microscopically evaluated shape change in stimulated human neutrophils, Neutrophil movement and chemotaxis is conventionally measured using Boyden chambers, which is a laborious and exacting technique. Microscopic scoring of neutrophil shape change has been shown to correlate well with Boyden chamber meas urements, and although less laborious, still requires manual counting. 2. We now show that measurement of forward angle light scatter in a b enchtop flow cytometer correlates closely with microscopic evaluation of neutrophil shape change in dose-response stimulation experiments wi th leukotriene B-4, N-formyl-methionine-leucine-phenylalanine or inter leukin-8. The relationship between shape change and increased forward angle light scatter was confirmed using the fluorescence-activated cel l sorter to separate partially stimulated neutrophils, followed by rea nalysis by flow cytometry and microscopic examination. 3. This flow cy tometric method provides a convenient, rapid and objective measure of neutrophil responses to external stimuli.