Blot (biology)

As blotting or blotting is known in molecular biology, a method for transfer of molecules such as DNA, RNA or proteins to a membrane. The name derives from the English " to blot " ( blot, stain, blot with blotting paper ) from which alludes to the course of action. The textbook The experimenter describes the blotting as the " attempt something that you have previously separated by electrophoresis in a gel permanently fix on a membrane ."

Edwin Southern led 1975 the blotting technique for DNA is referred to as Southern blotting. In accordance with its name, the blotting techniques later developed by George R. Stark for RNA Northern blot and Western blot for proteins than was called. There are also South Western blotting for DNA-protein and Far - Western blotting for protein-protein interaction analyzes.

The common principle

The investigated material ( DNA, RNA or proteins) is separated by gel electrophoresis. It is then a filter (usually nitrocellulose ) transfer (the actual blotting) and fixed irreversible. The next step is usually an antibody or a radioactively labeled probe ( gene probe in a nucleic acid, immunostaining of proteins ) is added. Gene probes remain only at the desired sequence liable ( hybridization ). The unbound probes are washed off and placed the filters on an X-ray film is exposed by autoradiography or chemiluminescence, and so indicates the results of the electrophoresis.