I don't know if your Dako antibodies are monoclonal or polyclonal, but going
to monoclonal has helped us.  We use antibodies from BioCare Medical, and
pretreat with 1mM pH 8.0 trisodium EDTA and BioCare's DeCloaking Chamber.
Even so, we still get some B5-fixed bone marrow biopsies that are all brown.
If the pathologists are just looking for plasma cells you might try staining
with no pretreatment-that seems to help.


Sally Ann Drew-MT(ASCP)
IHC/ISH Clin./Res. Laboratory
600 Highland Ave. VAH-DM223
Madison, WI 53792-2472
608-265-6596
sa.drew@hosp.wisc.edu


-----Original Message-----
From: Dana Settembre [mailto:settembr@UMDNJ.EDU]
Sent: Friday, January 26, 2001 2:56 PM
To: Histonet
Cc: Dana Settembre
Subject: Kappa & Lambda


Need help in reducing Kappa & Lambda background on bone marrow.
I use Dako's antibody, Kappa at 15K and Lambda at 18K, tonsil as a
control, citra MW 15 minutes for pretreatment.
Any suggestions?

Dana Settembre
Immunohistochemistry Lab
Pathology Department
University Hospital
Newark,  New Jersey
USA