A NEW APPROACH TO THE QUANTITATION OF MEM BRANE-BASED ON FLUORESCENCEENERGY-TRANSFER MEASUREMENTS

A new modification of the method for quantitation of membrane fusion b ased on measuring the resonance energy transfer between two fluorescen t probes incorporated in the same particle population was developed. T o improve accuracy of the method, the sizes of fusing particles, as de termined with laser spectroscopy, were taken into account. The method was applied to the Ca2+-induced fusion of two populations of phosphati dylserine vesicles, one of which was doped with two different Rhodamin e lipid probes comprising a donor-acceptor pair.