Southern, Northern, and Western blotting are techniques to detect specific biomolecules separated by gel electrophoresis. Southern blotting detects DNA using DNA probes, Northern blotting detects RNA using RNA or DNA probes, and Western blotting detects proteins using antibodies. All three techniques involve transferring the separated biomolecules from a gel to a membrane, probing with a labeled detection molecule, washing unbound probes, and detecting signals.