Fig. 11.
Adaptation of microfluorimetry to measurement of pHi in intact villous epithelium of murine jejunum using a horizontal Ussing chamber system. A: duodenal villi loaded with BCECF, a pH-sensitive ratiometric dye, and observed using a water-immersion objective. B: higher magnification of a single villus immobilized for pHi measurements using a nylon mesh overlay (not seen). C: higher magnification of upper villous epithelium with regions of interest for capture of fluorescence emission. [Reprinted by permission from Simpson et al. (44).]