IgM immunoprecipitation

[Jos Broers]

"D.K." wrote:
> 
> In article <0001HW.B9F741620009A529F0305600 at news.videotron.ca>, get real <allen at NOSPAM.icm.umontreal.ca> wrote:
> >On Tue, 12 Nov 2002 1:28:03 -0500, D.K. wrote
> >(in message <aqq71o$l8k$1 at news.doit.wisc.edu>):
> >
> >>  Jos Broers <Jos.Broers at molcelb.unimaas.nl> wrote:
> >>> Dear All,
> >>> Is it possible to perform an immunoprecipitation with protein-A
> >>> sepaharose beads and a mouse IgM antibody?
> >>> I doubt whether I get any binding.
> >>
> >> You are right, you won't have binding.
> >>
> >> Check Pierce catalog - if i remember correctly (not sure)
> >> there is something (lectin?) that binds IgM specifically.
> >>
> >> DK
> >
> >Try Protein G agarose or protein A/G agarose
> 
> I am reasonably sure protein G does *not* bind IgM.
> The lectin I was thinking about is called "mannan
> binding protein".
> 
> DK
Thank you all for your suggestions. Both the use of an additional step with an
anti-IgM antibody and the mannan binding protein seem promising. 
Btw, I looked into the literature and I did find some reports of certain types
of mouse IgM binding to prot-A, e.g.
Seppala, I., M. Kaartinen, et al. (1990). "Mouse Ig coded by VH families S107 or
J606 bind to protein A." J Immunol 145(9): 2989-93.

Jos