Semi-automatic analysis of unit channel conductance from voltage ramp records.

An IBM PC-compatible computer program, RAMP, for evaluation of single-channel recordings acquired using voltage ramp protocols is presented. The program uses semi-automatic procedures to make necessary corrections to a record (e.g. subtraction of baseline shift) and to measure all channel slope conductances as well as reversal potentials. The output is either a hardcopy of graphic display, which includes the calculated parameters, or data in ASCII format for further use (e.g. plots using various graphic software). Originally, the software was developed for the evaluation of voltage ramp records of single channel data from maxi chloride channels in myoblasts of a muscle cell line (Hurnák and Zachar 1992). Records from these membrane patches were also used in this work to demonstrate basic principles of the software and its practical use in evaluating single channel records obtained in response to the application of voltage ramps. The channel conductances calculated from ramp records were compared with those obtained by classical evaluation procedures from voltage step records.