PREPARATIVE ELECTROPHORESIS IN SIEVING MEDIA OF SUBCELLULAR-SIZED PARTICLES

The commercial gel electrophoresis apparatus with intermittent scannin g of the migration path and preparative capacity (HPGE-1000, LabIntell igence) is applicable to polymer solutions as well as gels. Unresolved rat liver microsomes can be isolated from 11-15% polyvinylpyrrolidone (PVP) solution by means of a syringe. The automated band isolation te chnique applied under resolving conditions in dilute polymer solutions allowed for the sequential isolation of three microsome components wi th 85, 76 and 75 % recovery, respectively, under strict control of the dimensions of the volumetric collection module of the HPGE-1000 appar atus. Separations of unlabeled microsomes and sea urchin egg component s in dilute polymer solutions have been performed, using detection by ''fluorescence reduction''. The unlabeled major component of a sea urc hin egg homogenate has been isolated from electrophoresis in 1.5% PVP (M-r = 10(6)) solution in 25-50% yield (0.24-4 mu g/8 lanes of the HPG E-1000 apparatus). However, since separations of both microsomes and s ea urchin egg granules in dilute polymer solutions are restricted to a narrow range of polymer concentrations, their retardation coefficient s, K-R,= d(log mobility)/d(polymer concentration), are not ascertained .