A general term for transferring molecules from an acrylamide or agarose gel in which they have been separated electrophoretically, to a paper-like membrane, usually nylon or nitrocellulose, maintaining the spatial arrangment. The binding interaction with the membrane can then be stabilized and the bound molelecules can be detected at high sensitivity by hybridization (in the case of DNA and RNA), or antibody labelling (in the case of protein). RNA blots are called northern blots, DNA blots are Southern blots, (named after E. Southern, who developed the technique), protein blots are western blots. In northwestern blotting protein is transferred but is probed with specific RNA. A simpler procedure, without a separation step, is the dot or slot blot in which a droplet or line of solution is put directly on to nitrocellulose paper and is then probed.
Subjects: Medicine and Health — Chemistry.