Transfer of nucleic acids or proteins from an electrophoretic gel strip to a chemically reactive paper or membrane (such as nitrocellulose paper) or matrix (nylon,, for5 example) - to which they bind. Blotting is achieved through capillary diffusion (when the gel is placed between the paper or matrix and an absorptive pad) or through electrophoresis (electroblotting). Of the three types of blots, Southern hybridization (or Southern blot) transfers DNA; Northern blots transfer RNA, and Western blots transfer proteins (also called protein blots).