Fig. 7. Cl^- removal-induced pH_i changes in partly denuded cumulus-oocyte complexes. Cumulus-oocyte complexes were partly denuded by careful pipetting with a narrow-bore pipette, and subsequently loaded with SNARF-AM. This allowed simultaneous visualization of the oocyte and attached granulosa cells (see inset). Cl^- was removed from the bathing media at 10 minutes. Fluorescence was measured separately in regions within the oocyte and within granulosa cell areas peripheral to the oocyte in order to monitor pH_i in the two compartments. Notice that Cl^- removal causes pH_i increases within oocyte and granulosa cells that are indistinguishable. Trace shown is the average of eight complexes in one of two similar experiments.