1. As a verb, this means to transfer DNA, RNA or protein to an immobilizing matrix.

2. As a noun, it usually refers to the autoradiograph produced during the Southern or northern blotting procedures. The variations on this theme depend on the molecules:

– Southern blot: the molecules transferred are DNA molecules, and the probe (q.v.) is DNA.

– northern blot: the molecules transferred are RNA, and the probe is DNA.

– western blot: the molecules transferred are protein, and the probe is labelled antibody.

– Southwestern blot: the molecules transferred are protein, and the probe is DNA.

– dot blot: DNA, RNA or protein are dotted directly onto the membrane support, so that they form discrete spots.

– colony blot: the molecules (usually DNA) are from colonies of bacteria or yeast growing on a bacteriological plate.