Gustave,

I can't offer a direct answer with regards to the molecular
characteristics of CD29, but instead can just give specifics to IHC
techniques.  I would expect membrane staining using this particular
antibody.  If you are getting nuclear staining, I would recommend taking
a look at your retrieval technique.  It would be you are
"over-retrieving" for this antibody in your samples.  Many antibodies
that errantly stain nuclei end up needing less antigen unmasking, and/or
require further dilution.

Make sure your secondary antibody is adsorbed to mouse.  Rat and mouse
are similar and sometimes anti-rat secondaries can cross react in mouse.
(I doubt this is the cause of your problems).

Perhaps you can work this up using control tissues instead of your
sample; this marker is known to stain lymphocytes, so perhaps thymus or
other lymphoid material might suffice and see if you get the same
staining patterns.

Finally, you might consider using a different fixative, or try staining
on frozen section and see if you get the same results.

Good luck!

Teri Johnson
Managing Director Histology Facility
Stowers Institute for Medical Research
1000 E. 50th St.
Kansas City, MO 64133