Inappropriate conversion of current magnitude to current density may misinterpret results

The magnitude of ionic current (I, in pA) is usually assumed to increase proportionally to the membrane area roughly estimated by measurement of the membrane capacitance (C, in pF). Hence, to lower differences of data measured in cells with varying cell membrane areas, the current density (J, in pA/pF) is routinely calculated as I/C ratio. However, if the I-C correlation was weak and insignificant, the conversion to J would be inappropriate and, if performed, could considerably change the interpretation of results.