Separation of cells having histochemically demonstrable glucose-6-phosphatase from suspensions of hamster kidney cells in an isokinetic density gradient of Ficoll in tissue culture medium.

Suspensions of enzymatically disaggregated hamster kidney cells were separated primarily according to differences in diameter using velocity sedimentation in a previously described isokinetic density gradient and according to differences in density in an isopycnic density gradient. Cells which contained histochemically demonstrable glucose-6-phosphatase were thought to be cells from proximal tubules and constituted 46.5 +/- 14.1% of the cells in the starting sample suspension of disaggregated kidney cells. The purest gradient fractions from experiments using velocity sedimentation contained 98.0 +/- 0.6% cells which demonstrated glucose-6-phosphatase activity. More than 99.0% of these cells excluded trypan blue. Isopycnic sedimentation was not an effective means of purifying proximal tubule cells.