Immunoprecip gurus?

Sean Patterson seanpat at FMED2.UNCU.EDU.AR
Thu Nov 18 08:02:02 EST 1999

>Ok, let's say protein A binds to protein B which binds to protein C.  If
>I pull down with an antibody to protein C (from cell lysates), should I
>expect to be able to pull down protein A with it and probe for protein A
>on a Western, or is it too much to hope for that everthing will stay
>together during the IP?  I'm sure it depends on dissociation contants,
>but generally speaking...

A couple of thoughts.......

	If your antibody requires denaturation to see the epitope you won't
IP anything - polyclonals which recognize multiple epitopes would be
better. It would also be unfortunate if your epitope was shielded in the

	If you can also get antibodies to A and B (if their identity is
known) you should also be able to bring down the same complex using
different antibodies, a control that Harlow & Lane strongly recommends to
avoid embarrasing errors.

	Try it and see, you never know.

Sean Patterson, Ph.D.
Catedra de Fisiologia, CC33
Facultad de Ciencias Medicas
Universidad Nacional de Cuyo
Mendoza, Argentina
Tel: (0261) 420-5115 ext.2684/2747
Fax: (0261) 449-4117
e-mail: seanpat at

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