Jeannette,
Microwaving in citrate buffer is really overkill for factor XIIIa staining
and results in increased background or inappropriate positive staining. I
use the Sigma trypsin tablets  for 30 minutes at 37degrees C. For the
antibody, I use a 1:400 dilution in PBS with 1% BSA added, incubate for 30
minutes at room temp.  A good control is placenta or a dermatofibroma,
normal skin has a few small inconspicuous dermal dendrocytes in the
papillary dermis while placental villi have a striking population of
FXIIIa+ stromal cells, as do most dermatofibromas.  Hope this helps and
don't hesitate to call or email for more advice if needed.  This is my
favorite antibody (antiserum)!
Jeff Silverman
Southampton Hospital NY USA
peptolab@hamptons.com
516 726-8969
----------
> From: Mitchell, Jeannette M. <Jeannette.Mitchell@vtmednet.org>
> To: 'histonet@pathology.swmed.edu'
> Subject:
> Date: Tuesday, November 17, 1998 9:38 AM
>
> Hello my histonet friends,
>
> I am writing in regards to the antibody Factor Xlll Subunit A purchased
from
> Bogenex.   We have been having problems with correct staining.  We are
> currently using a dermal dendrocyte for a control.  The tumor stains but
> also do the sweat glands and in fact they stain more intensely than the
> tumor cells.  Does anyone  have any ideas?  We do use the Antigen
Retrieval
> Citra Solution and have tried various dilutions.
>
> Thanks for any help that is provided
>
> Jeannette Mitchell