One-step separation of endocytic organelles, Golgi/trans-Golgi network andplasma membrane by density gradient electrophoresis

Many different methods for the fractionation of subcellular organelles have been reported. However, no protocol for rapid separation of plasma membran e, Golgi/trans-Golgi network (TGN) and endosomes is available to date. Such a method is a prerequisite for a quantitative biochemical analysis of vesi cular transport from the Golgi/TGN compartment to plasma membrane and endos omes. Here a density gradient electrophoresis protocol is described that al lows the fractionation of these organelles in one step. This protocol requi res only low-cost instrumentation available in most biochemical laboratorie s.