Western blotting technique is used to detect protein of a particular specificity. Particularly when it transferred gene expresses in transformed cells, the translated product in the form of protein can be identified by this technique.
The extracted proteins are subjected to polyacrylamide gel electrophoresis and are then transferred onto nitrocellulose, to which they bind. Nitrocellulose membrane is then used for probing with a specific labelled antibody. The antibody may be labelled with iodine – 125 and the signal is detected again with autoradiography.
If a radioactive labelled is not used, bound antibody may be detected by a second antibody tagged with an enzyme.