Western blot uses monoclonal and polyclonal antibodies.
Western blot does not recognize proteins. Western blot monoclonal antibodies recognize a protein which is present in natural cell supernatant or fluid named an antigen.
The antigen has an epitope. Usually the epitopes used to inject mouse for monoclonal and rabbits for polyclonal antibodies are not larger than 35 amino acids and larger than 10 amino acids.
Alternatively whole protein can be injected with KLH into mouses or rabbits.
Monoclonal recognize one specific epitope or part of that epitope.
Poly-clonal antibodies recognize different epitopes but since in an epitope of only 35 amino acids is very small most polyclonal are like virtual monoclonal antibodies. Often there is 1 dominant epitope even in whole protein immunizations.
Antibodies are very powerful tools. dilution of 1/500 are used for WB incubation. Most companies sell 100 ul that will give 50 ml of incubation reagent. Concentrations are often 100 ug /ml. Santa Cruz, in California close to San Francisco sells 200 ul antibody vials.
Western blot can discriminate between proteins which are present in natural serum of cell extract and they cannot differentiate between DNA.
An example of this is when antigens are found in both cell supernatural or cell extract for extracellular proteins.
Only when antibodies are bound to a molecular marker or to a secondary anti rabbit or mouse, than a response will be generated.
In the human body, Antibodies are essentially used to avoid rejection of the transplanted cancerous cells. Antibodies bound to antigens produced by the cancer cells, the antibodies will prevent them from being properly accepted by the host cells. Antibodies are also necessary in diagnosing and in treating cancer. The antibodies can be used to identify cancer cells, but there are other techniques which use antibodies. Antibodies are also used to protect cells from natural or synthetic contaminants. A lot of research has been done in the last few years to detect cancer cells. The antibodies in cancer cells can block the effectiveness of immune cells in fighting cancer.