Blotting:  a basic molecular biology technique originally created by Edwin Southern
        for locating gene specific sequences on DNA fragments isolated from cell.

 SOUTHERN BLOTTING*: is used to locate and identify genes on DNA fragments.  
        Restriction Fragments are electrophoretically separated and then melted to give ssDNA pieces.
        The fragments are blotted onto nitrocellulose or nylon membranes, where the DNA bonds
        permanently. Hybridization with labeled DNA probes & autoradiography localize target DNAs.
        To find a gene one must have a DNA sequence that is complimentary to some region on fragments.

NORTHERN BLOTTING: a variation on Southern blotting (a humorous analogy?) where a cell's
        RNA's are separated by electrophoresis, transferred to filter paper, and probed with a labeled
        ssDNA probe.

WESTERN BLOTTING: another variation involves separating proteins via electrophoresis and then
        probing the resulting filter paper  with an antibody that binds to the protein your are interested
        in locating.
back