Is the surface charge on granulocytes really decreased following their exposure to chemotactic factors?

The mean axial ratio of polarised granulocytes has been determined and interpolated with plots relating settling factors (the inverse of relative frictional coefficients) to the axial ratios of simple isotropic solids. The estimate for the relative frictional coefficient of polarised granulocytes obtained by this procedure (f/fo = 1.11) suggests that a change in cell shape can account largely for the previously observed decreases in granulocyte electrophoretic mobility that occur following exposure to chemotaxins. In consequence, the widely held view that chemotaxins induce an alteration in cell surface charge is open to re-appraisal.