Blotting analysis allows scientists to transfer electrophoretically separated components from a gel to a solid support. This support may then be used for probing with reagents specific for particular sequences of amino acids or nucleotides. In this way, the size and/or quantity of the proteins or nucleic acids under study can be gauged.

Blotting analysis was originally developed in 1975 by British molecular biologist E. M. Southern while he was on a leave of absence from his Edinburgh lab to do research in Zurich. This process has since been referred to as Southern blotting. Southern's method was designed to transfer fragments of deoxyribonucleic acid (DNA) from the agarose gel in which they had been separated onto cellulose nitrate filters. The DNA fragments are deposited onto a filter laid over the gel as a result of capillary action, which is established and maintained by the flow of...