Monoclonal vs Polyclonal Abs - (Jul/27/2008 )

Hi all,

Wondering what's the difference between mono- and polyclonal antibodies? I understand the part about polyclonal having several isotypes? whereas monoclonal having only one.

How would this affect Western blot results? Will the monoclonal Ab give a cleaner blot?

What are the pros and cons of each?

I guess I've probably came across this in my undergrad days, but have long since forgotten them..

Can someone please enlighten me? THanks!

regards,
shyn

Polyclonal sera contains a population of many different antibodies (each produced a a different B-cell clonal line, thus "polyclonal") directed against many different epitopes.

Monoclonal sera contains many of a single antibody (produced by a single B-cell clonal line, thus "monoclonal") directed against a single epitope.

Monolonal antibodies will usually give a "cleaner" blot, and -- if the epitope to which they're directed only exists in a single protein in your western sample -- will be specific for that protein.

If all the epitopes to which the population of antibodies in your polyclonal sera are directed only exist in a single protein in your western sample, polyclonal sera will be specific to your protein; however, if one or more of the targeted epitopes exist in other proteins in your preparation, the polyclonal sera will detect these proteins too.