I am doing whole-cell voltage clamp in HEK cells and would be very grateful if you share with me your experiences of measuring the reversal potential of an overexpressed channel. How different are the values you obtain between different individual cells that express the same channel?
Theoretically, it should only depend on the ion gradients (set by the bath and pipette solutions) and properties of the channel, and thus should be fairly reproducible from cell to cell. But, I get a rather broad distribution of the values with a half-bandwidth about 40 mV measured in different cells, and cannot figure out the reasons for it. Thank you very much in advance.