Fig. 1. The time course of eosinophil depolarization correlates with activation of the proton conductance. (A) Eosinophils were loaded with 600 nM diBAC₄(3) and analzyed at room temperature by confocal microscopy (magnification=630). Inset is a 3 electronic magnification of the area in the box. A representative experiment is shown (n=4). (B) Eosinophils were stimulated with 800 nM PMA at room temperature. Depolarization (; n=26) was assayed using diBAC₄(3) and flow cytometry as described in Materials and Methods. Conductance values (; n=6) were calculated from current measurements following a voltage step from the holding potential (–60) to +80 mV.