Marcia,

If it were me, I would go with the rat anti-human CD77 followed by a
biotinylated anti-rat IgM that was preferably adsorbed against mouse tissue.
Many companies offer anti-rat IgM (ie. Jackson ImmunoResearch, Biogenex,KPL,
maybe Innogenex---Abizar are you there?). Call around and see if any are
mouse adsorbed. I use an anti-rat IgG from Biogenex that is mouse adsorbed,
maybe they have an IgM. 

I don't think that rat IgG will bind the rat IgM, it depends on how purely
it is prepared. However sometimes these secondaries are actually a mixture
of IgA, IgM, and IgG). 

I would also call tech services of the CD77 supplier and ask them if they
have any data on crossreactivity with the antibody.

Lastly, when you decide to enroll in another immunology class, sign your
boss up too.

Regards,
Brett


Brett M. Connolly, Ph.D.
Merck Research Laboratories
Department of Pharmacology
WP26A-3000
PO Box 4
West Point, PA 19486
Ph. 215-652-2501
FAX 215-652-2075
e-mail: brett_connolly@merck.com


> ----------
> From: 	Marcia Bentz[SMTP:mb7x@virginia.edu]
> Sent: 	Thursday, October 19, 2000 6:48 AM
> To: 	histonet@pathology.swmed.edu
> Subject: 	IHC with IgM
> 
> Hello all,
> Ended up dropping my immunology class several years ago due to a serious
> illness and need the answer to a question. By boss is looking for an
> antibody CD77 (if wishes could come true, anti-mouse). Two problems arise,
> this is a IgM and I've only worked with IgG. I also only seem to be able
> to
> find mouse or rat anti-human CD77(I am staining mouse kidney). Since I use
> the Vector Elite kits will the rat IgG work with an IgM primary?. My boss
> insists it will, but well... he doesn't always know what he's talking
> about
> and has difficulty understanding IHC techniques sometimes.He also insists
> there will be no cross reactions with mouse or rat proteins. Can anyone
> answer this question for me?
> 
> Thanks!
> 
> Marcia
> Marcia Bentz
> Lab Specialist Sr
> University of Virginia
> Medicine/Nephrology
> mb7x@virginia.edu
> 804-982-1069
> 
>