Abstract: A device and process for inducing membrane fusion under an electric field. The process comprises the steps of (a) suspending said membranes in an aqueous buffered medium in a manner so that the membranes are without contact with each other; (b) altering said membranes to a fusogenic state by applying 2-30 pulses of direct current at a rate of 2 to 5 pulses per second in an electrical field strength of about 500-1000 volts/mm in the medium, said pulses having a rapid rise time not exceeding about 10 micro seconds and an exponential decay half time of about 0.2 milliseconds to about 1.2 milliseconds; and (c) thereafter bringing said fusogenic membranes in contact with each other. A long-lived metastable fusogenic state of membranes can be obtained by the device and process.