Fig. 10
The tdTomato reporter facilitates visualization of cultured CPECs on Transwell membranes. A CPECs growing on Transwell membranes are not easily visible using phase contrast microscopy. B When visualized using red epifluorescence, the same field as in A could be seen to possess a confluent monolayer of primary CPECs originally dissociated from the ChP of homozygous TTR BAC-tdTomato transgenic mice (3147 founder line). C Stitched images of tdTomato fluorescence revealed nearly 100% coverage of the Transwell membrane after 4 days of undisturbed culture. The monolayer displayed a respectable trans-epithelial electrical resistance of 110 Ω cm2. D The same membrane as in C was imaged after 3 days of experimental manipulation. Holes in the coverage were clearly evident (arrows), explaining a measure decrease of resistance to 44 Ω cm2