----- Original Message -----
From: "Sebree Linda A." 
To: "Histonet" 
Sent: Thursday, April 10, 2003 9:29 AM
Subject: biotin containing tissues


> Does anyone out there have a good reference or list of tissues containing
endogenous biotin?  We don't like to put avidin-biotin block on our staining
procedures unless the tissue requires it.  We're aware of liver and kidney
but there are other tissue types that also contain biotin to a lesser
degree.  Thanks for your help.
>
We have noticed a large amount of biotin in breast core biopsies.  Almost
any tissue can have biotin levels increased by heat mediated antigen
retrieval.    I have also seen biotin specifically expressed in several
tumours.  Needless to say this is a really good reason to always check
negative controls. Tom

Tom Wells, BSc, ART
Immunohistochemistry Supervisor
Lions Gate Hospital
North Vancouver, BC
Canada