Protein Blotting

Protein blotting was initially introduced in the late 1970s to identify protein antigens that bound to spectfic antibodies (,) In this procedure, a complex protein fraction was separated by electrophoresis and the proteins transferred and bound to a membrane, which was then probed with a radiolabeled antibody This concept and procedure were based on blotting and hybridization methods developed for DNA by Southern () (and logically called Southern blotting), which was subsequently modified for RNA () (less logtcally called Northern blotting by some authors). It is, therefore, not surprising that the protem/antibody procedure was called Western blotting (), and that Southwestern (protein/DNA) and Far Western (or West Western) (protem/protem) procedures have since been developed In addition, it is possible to apply proteins to the membrane in solution (dot-blotting), or to transfer them directly from tissues (squash blots and tissue prints), whereas the development of microscale protein sequencing and ammo-acid analysts has allowed the use of blotting to purify and characterize individual components of highly complex mixtures