If I remember well, I have found reactivity in lymphoid tissue and intestine (in sheep and rabbit).  I have incorporated a biotin block into all my stains requiring amplification, as we use the LSAB2 components from Dako.
Albert

>>> Fred Underwood  04/10/03 10:54AM >>>
You can add brain to that list.  A possible reference is , Appl. Immunohistochem: issue 5, 1997.  I have swithced to a non-biotin amplification kit from Zymed.  
1-800-874-4494, www.zymed.com.  Additional info on this kit is in JOH volum 23, #4 December 2000.
 
Fred

	-----Original Message-----
From: "Sebree Linda A."  
Sent: Thursday, April 10, 2003 12:29 PM
To: Histonet 
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.

	Linda A. Sebree, HT(ASCP) 
University of Wisconsin Hospital & Clinics 
IHC/ISH Laboratory 
A4/204 2472 
600 Highland Ave. 
Madison, WI 53792 
(608)265 6596 
FAX: (608)262 7174