Co-IP problems

Allison via (by allison from
Tue Dec 16 10:48:20 EST 2008

Fulvio Celsi wrote:
> Dear All
> I'm looking for  suggestions on CoImmunoPrecipitation.... The protein 
> I'm interested in CoIP has a MW of 75Kd, so any time I made the 
> experiment, on the CoIP lane I saw a smear from the Igg (around 60kd if 
> I know well). How can I reduce this effect? I cannot buy another Ab 
> (from a different species) thing that I suppose would help...can I 
> cross-link ab to the protein-A beads? if
> Thanks a lot in advance
> Fulvio

Could you run a non-reducing gel?  Then the IgG would run at 150K vs 75K 
for your protein (assuming the latter is not subunits as well).

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