Free-flow electrophoretic analysis of endosome subpopulations of rat hepatocytes

Endosomes constitute a functionally, morphologically, and biochemically heterogeneous population of intracellular organelles that play a major role in sorting of incoming ligands, receptors, membrane, and lumenal content. This unit provides protocols for labeling and isolation of endosomes of polarized rat hepatocytes. By application of free-flow zone electrophoresis functional endosomal subcompartments involved in transports to lysosomes and transcytosis are resolved from each other. Methods to analyze the protein composition or acidification properties of these highly purified endosomes are also described.