Membrane Protein Fractionation and Analysis through Western Blot in Aedes aegypti Malpighian Tubules.

Western blot analysis is a well-known and dependable technique used to quantify protein abundance in a wide variety of samples. A major consideration for running a successful western blot is ensuring that the protein to be analyzed is purified appropriately. For work with membrane-bound proteins, traditional methods of protein processing such as the use of high-frequency sonication and ultracentrifugation to separate proteins from the membrane are being replaced with less time-consuming approaches. The use of a membrane fractionation kit, which involves the separation of membrane proteins from soluble (cytosolic) proteins, is effective in allowing for the quantification and analysis of membrane-bound proteins. In this protocol, we describe use of the membrane fractionation kit to isolate membrane-bound proteins, followed by western blot analysis, to observe protein abundance. The protocol involves methods that require organ (or tissue) collection, followed by protein processing, and a 2-d western blot procedure.