I do HBV staining using a DAKO kit.  The first thing I do is block Avidin
and biotin with the DAKO blocking kit, then the H2O2 (3% for 10 min).  This
has eliminated virtually all background staining.  Do you block for
endongenous biotin and avidin?  If not, and you're still getting the
background staining, you may want to block those as well as the peroxidase.
 Just a thought...

Connie McManus


At 06:48 PM 06/06/2000 -0400, JennieLynn6176@aol.com wrote:
>We currently treat some of our slides, such as kappa and B and T cell 
>markers, with hydrogen peroxide prior to staining to reduce the background 
>staining that we were getting.  If anyone else does this, do you know if 
>there is a time limit that you should not exceed in the hydrogen peroxide?  
>Currently we are immersing 10-15 minutes in the hydrogen peroxide before 
>loading onto a Ventana automated stainer.  I wanted to know if an increase
in 
>time would  #1-reduce more of the background, #2- just be a waste of time,
or 
>#3 would damage the tissue and results.  Thanks in advance for a response.
>
>Jennifer Macias, HT (ASCP)
>Forum Health
>Western Reserve Care System
>Youngstown, Ohio
>
>