Polyclonal And Monoclonal Antibodies What Is The Difference?
An antibody catalogue from a major supplier of antibodies will offer several antibodies of the same substance
. Some will be polyclonal and some monoclonal. Choosing between these two types is the first decision a researcher has to make.
Polyclonal antibodies are cheaper, because they are much simpler to produce. Animals are injected with the substance of interest. The animals produce antibodies, which are released into the blood. Serum is collected from the animals. The antibodies are then isolated from the serum.
Monoclonal antibodies require more complex technology and thus are more expensive to produce. Antibody-producing cells (B cells) from the spleen of an immunised animal are fused on a one-to-one basis with B cells originally obtained from a B cell cancer. The cancer cells do not produce antibodies themselves. The resulting hybridoma is immortal like a cancer cell, but also produces antibody. The hybridoma is grown in culture to obtain many identical antibody-producing cells. The antibodies are harvested from the culture medium.
A polyclonal antibody is actually a mixture of antibodies from lots of different B cells. They vary in how well they recognise the substance (specificity). Some of these antibodies will also recognise other substances with a similar structure. A monoclonal antibody derives from one parent cell so all the molecules are identical. It is highly specific for one particular structure on the substance of interest.
The choice of antibody depends on how it will be used. If high specificity is needed, a monoclonal antibody may well be best. However, monoclonal antibodies can sometimes be too particular. If the substance of interest undergoes chemical changes or becomes degraded, a monoclonal antibody might no longer recognise it. In this case, the broader specificity of a polyclonal mixture may be a better choice.
Contact us at Novus Biologicals for any information or assistance with regard to antibodies. Our antibody catalogue is a resource that many researchers benefit from utilising.