Figure 2. Time course for the development of an outward current in COS-7 cells expressing gp91^phox and in non-transfected COS-7 cells.

The currents elicited by a depolarizing voltage pulse to +60 mV (A, B) or +20 mV (C, D) were recorded in COS-7 cells expressing gp91^phox (A, C) and in non-transfected COS-7 cells (B, D) at the time points shown after establishment of the whole-cell conformation. Between pulses, the cells were maintained at −60 mV. The time course for the equilibration of the pipette solution with the cell cytoplasm was monitored through the inclusion of 0.2% (w/v) Trypan Blue in the pipette solution (E). The development of the current was recorded during the time course (E). Still photographs of the progress of equilibration were taken at 0 min (i), 5 min (ii), 12 min (iii), 25 min (v), 32 min (vi), 42 min (viii), 52 min (x) and 65 min (xii) following the establishment of the whole-cell configuration. Recordings of the outward current elicited by a depolarizing pulse to +20 mV were obtained at 15 min (iv), 35 min (vii), 45 min (ix) and 55 min (xi) following establishment of the whole-cell configuration. The bath solution was at pH 8.0, and the bath temperature was maintained at 22 °C throughout.