Proud to be a Ventana user, also? Anyway. Your problem might be the Ventana
secondary antibody. Clone DBA.44 is an antibody of the IgM class (most
primaries are IgG1, some are IgG2a, IgG2b or even IgG3). Most secondary
anti-mouse antibodies show some, but usually only limited crossreactivity
with primary antibodies of the IgM class, they work far better with IgGs. As
a consequence, monoclonal IgM-primaries stain anywhere between weakly to not
at all, when combined with a 'standard' secondary antibody. In open
automated systems or when doing manual staining you always have the option
to replace your regular secondary antibody wtih one that is specifically
directed against mouse IgM. So when staining DBA.44 with e.g. gt-a-mo
IgM/Biotin as the secondary antibody you get far better results than with a
simple gt-a-mo Ig/Biotin secondary. If your BenchMark gives you a chance,
try it - otherwise try it manually. Futhermore, although some suppliers
suggest an enzymatic pretreatment for DBA.44, we've got far better results
with HIER (pressure cooker, citrate). Good luck!

Andi Kappeler
Institute of Pathology, University of Bern, Switzerland

----- Original Message -----
From: "Kim Saunders" 
To: 
Sent: Friday, June 27, 2003 4:59 AM
Subject: DBA.44


> Is anyone out there running the DBA.44 on the Ventana BenchMark and
getting successful results?    Kim Saunders - HT  St. Joseph Hospital
(Tucson, AZ)
>
>
> Kim Saunders
> Proud to be an American!!
>
> ---------------------------------
> Do you Yahoo!?
> SBC Yahoo! DSL - Now only $29.95 per month!
>