A membrane fusion strategy for single‐channel recordings of membranes usually non‐accessible to patch‐clamp pipette electrodes

Membranes of cellular organelles and plasma membranes of some type of cells are not accessible to the high-resolution recordings that the conventional patch-clamp technique allows. However, when these purified membranes are dehydrated together with small lipid vesicles and hydrated again, cell-size vesicles (5-100 micron diameter) are obtained, on which single-channel recordings are possible. This approach, which has been proven successful with about ten different membrane preparations of varied origin, is further illustrated with two examples. First, a known conductivity of the sarcoplasmic reticulum membrane is compared with data obtained by using other techniques. Second, a new sodium current, present at purified postsynaptic membranes from the Torpedo electric organ, is described.