Di-8-ANEPPS labeling of the PM. a, Transmitted image of an OHC undergoing micropipette aspiration (−11 cm of H₂0). b, The simultaneous fluorescent image of a demonstrates staining of thePM. The apex of the cell is out of the focal plane in this image; however, the stereocilia were always labeled.c, Transmitted image of a vesicle that was released as the suction pressure was increased (−15 cm of H₂0).d, The fluorescent image shows that the vesicle contains PM.