Abstract
The nonlethal procedure of incubation in EDTA solution makes the peripheral regions of ascites sarcoma 37 cells more easily deformable, as reflected in measurements of the decreased amount of negative pressure required to suck out standard hemispherical bulges from the cells into micropipettes. The facilitation of deformability was abolished after reincubation of cells in calcium-containing saline, and this mechanical parameter was partially restored to normal after reincubation in magnesium-containing saline; the mechanical effect of EDTA treatment is, therefore, thought to be due mainly to the removal of calcium from the cell periphery. As EDTA treatment produces no detectable change in cellular electrophoretic mobility, it is concluded that peripheral calcium must be bound to anionic sites deeper than about 10 A from the cellular hydrodynamic slip plane. The data are discussed with emphasis on the view that they should not be extrapolated freely to other cell types.