[Histonet] excessive IHC background staining

[Daryl Mikita]

Hello Everyone,

I have been running into an issue with Synaptophysin with antigen retrieval.  I currently use a piece of pancreas for the Synaptophysin control on the same slide as the patient tissue.  When I run this IHC on a non-necrotic piece of tissue, it works great.  When the patient tissue is necrotic I get excessive background on both the patient and control tissue.  What is going on here.  We use a peroxidase block, but no avidin-biotin block or protein block.  I have tried an avidin-biotin block at the urging of technical support, but it did not change anything. Also, a negative control (patient tissue with negative control reagent) is clean.

Thanks,

Daryl Mikita, HT(ASCP)cm
Wyoming Medical Center
Anatomical Pathology
1233 E. 2nd St.
Casper, WY 82601
Phone: 307-577-2198
Fax: 307-577-2731