viability of the cells of everted diluting segments taken from ambystoma kidney was indicated by 1 ) failure of the cells to take up trypan blue and 2 ) the existence of an apical membrane voltage ( average 66 mv , cell negative ) , which decreased predictably in the presence of either 5 mm barium or elevated potassium in the luminal bathing solution .
C0007620
viability
C0007634
cell