A comparison of K+ channel characteristics in human T cells: perforated-patch versus whole-cell recording techniques.

Standard whole-cell records using the patch-clamp technique are obtained after rupturing the cell membrane just below the patch pipette. Inherent problems, such as the disruption of cellular architecture and the displacement of cytosol, are unavoidable. In the present report, a whole-cell recording technique which makes use of a monovalent cation ionophore, nystatin, was applied to lymphocytes. Nystatin-perforated patches allow electrical access to the cell interior while virtually blocking the diffusion of cellular constituents into the electrode. By comparing standard whole-cell and perforated-patch techniques we observed marked differences in: activation, inactivation, and deactivation kinetics; steady-state inactivation; and the conductance-voltage relationship of K+ currents in activated human T cells.