Human multiple tissue western blots: a new immunological tool for the analysis of tissue-specific protein expression.

Human multiple tissue Western (MTW) blots are premade immunoblots prepared using proteins isolated from adult human tissue. The proteins are isolated from whole tissue homogenates under conditions designed to minimize proteolysis and to ensure maximal representation of tissue-specific proteins. Sodium dodecyl sulfate (SDS) solubilized proteins are fractionated by SDS polyacrylamide gel electrophoresis and electroblotted onto polyvinylidene fluoride membranes to generate blots ready for incubation with researcher-supplied antibodies. Each lane of an MTW blot contains an equivalent amount of total protein, allowing for the analysis of tissue-specific expression of a particular protein(s). The utility of MTW blots for Western blot applications was demonstrated by the detection of various cytoskeletal proteins and members of the annexin family of calcium-dependent, membrane-binding proteins. Several of these antigens were detected in separate cycles of antibody incubations using the same MTW blot. This approach is possible using a stripping procedure that allows the researcher to selectively remove both primary and secondary antibodies in a single incubation. The ease of multiple reprobings makes MTW blots both economical and convenient research tools for Western blot analyses of human tissue-specific proteins.