Isolation of subcellular-sized particles separated by electrophoresis in dilute polymer solution, using commercial electrophoresis apparatus with intermittent scanning of fluorescence

Resolution cf subcellular-sized particles in electrophoresis employing semidilute polymer solutions as ''sieving media'' improves as the polymer concentration is decreased. Therefore, the previously reported conditions of preparative electrophoresis of microsomes, using concentrated (12%) polyvinylpyrrolidone (PVP) solutions, while solving the problem of non-entrance of large particles into ''sieving media'', do not provide adequate resolving capacity, as exemplified by failure of the microsome preparation used, to resolve in the manner of gels or dilute solutions. The present report provides the conditions under which the HPGE-1000 apparatus can be preparatively applied when the electrophoretic separation is effectively conducted in a dilute polymer solution. The isolation of three microsome components under those conditions constitutes the first application of ''particle sieving'', i.e., a separation due preponderantly to size and shape differences, at a preparative scale.