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.