Proteomic profiling of subcellular compartments has many advantages over traditional proteomic approaches using whole cell lysates as it allows for detailed proteome analysis of a specific organelle and corresponding functional characteristics. The microsome is a critical, membranous compartment involved in the synthesis, sorting, and secretion of proteins as well as other metabolic functions. This chapter will describe detailed methods for the isolation of microsomal organelles including the ER, Golgi, and prechylomicron transport vesicle (PCTV), a recently identified vesicular system involved in intestinal lipoprotein assembly and secretion. Particular focus is given to the isolation of microsomes from primary hepatocytes and enterocytes freshly isolated from rodent liver and intestinal tissue, and their proteomic profiling using a combination of two-dimensional gel electrophoresis and mass spectrometry.
