mAB vs pAB - (Nov/16/2008 )

Dear all,

Is there any differences between monoclonal antibody and polyclonal antibody other than the price difference? ( i know mAB is more expensive than pAB) As I was always recommended to purchase mAB, but i can only find pAB for the protein i am going to study, as best as i can.

Thanks

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it depends on the scientific goal: if you analyze mutated forms of a polypeptide a polyclonal would be the choice over mAb as the specific antigen epitope may be affected; if the antigen epitope for the mAb is intact, the mAb will be prefered as cross reactions may be lower than with pAb...

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I agree. If you can only get poly make sure you obtain it as an affinity purified product. That will eliminate all abs that do not recognize your ag. But you will still have abs that differ in their reactvitites.

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Sorry, what's mean by affinity purified product? How can we tell it is an affinity purified product?

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Affinity purified polyclonal antibodies are a population of antibodies that have been cleared of antibodies that don't recognize an epitope on the antigen. Basically, your antigen (usually protein) is immobilized on a column and the polyclonal antisera is passed over it. Any antibodies that recognize an epitope on your antigen are retained, and others pass through. The antibodies are then released from the antigen and collected, so what remains are antibodies that recognize at least one epitope on your antigen.

Since many antigens have several epitopes, there will still remain a population of antibodies each of which recognizes one of the (presumably) several epitopes on your antigen, as opposed to a monoclonal antibody, that recognizes one and only one epitope.

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