[Histonet] TTF-1 Staining

[Robert L. Lott]

Subject: TTF-1 Staining



For those of you who participate in the CAP/NSH HistoQIP program... and did so in back in 2009, one of the IHC challenges that year was TTF-1.

>From the critique published with that particular challenge, enrolled participants may have read with interest the following 2 excerpts: (I have included the references)


        The majority of the published studies on the immunoreactivity of TTF-1 have been conducted using two commercially available clones, 8G7G3/1 and SPT24. 

        It has been shown that SPT24 is more sensitive than 8G7G3/1 for the detection of pulmonary adenocarcinomas.      

        In a comparative study of 86 primary pulmonary adenocarcinomas by Comperat et al., nuclear staining was detected in 72 cases (84%) with SPT24 and 56 cases (65%) with 8G7G3/1.6



        

        The clone 8G7G3/1 cross reacts with cytoplasmic mitochondrial proteins in liver cells while the clone SPT24 does not. 

        Pathologists have taken advantage of this phenomenon and used it to study carcinomas of the liver.  

        In a recent study, cytoplasmic reactivity for TTF-1 was observed in 71% of hepatocellular carcinomas with the 8G7G3/1 antibody and was more sensitive than Hep-Par 1. 

        The cytoplasmic reactivity is seen even when using biotin-free protocols and seems fairly specific for hepatocellular carcinoma.11

 

        
        6.  Comperat E, Zhang F, Perrotin C, Molina T, Magdeleinat P, Marmey B, Regnard JF, Audouin J, Camilleri-Broet S. Variable sensitivity and specificity of TTF1 antibodies 

             in lung metastatic adenocarcinoma of colorectal origin. Mod Pathol. 2005; 18(10):1371-1376.

        

        11. Pang Y, von Turkovich M, Wu H, Mitchell J, Mount S, Taatjes D, Cooper K. The binding of thyroid transcription factor-1 and hepatocyte paraffin 1 to mitochondrial 

              proteins in hepatocytes: a molecular and immunoelectron microscopic study. Am J Clin Pathol. 2006;125(5):722-726.




Robert L. Lott, HTL(ASCP)


 -----Original Message-----
 From: histonet-bounces <@t> lists.utsouthwestern.edu
[mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Paula Lucas
 Sent: Thursday, February 03, 2011 2:38 PM
 To: Subject: [Histonet] TTF-1/background staining
 
How can I eliminate the background or as you say, non-specific staining?
 
I'm no expert here, I admit, and so I'm asking for your help and suggestions. I have searched the Histonet archives, and a lot of what I'm
seeing deals with animal or rodent tissues, and a lot of it was confusing to me.

To give you a little background info:
 
We use the Lab Vision stainer and the TTF-1 antibody we use is from Cell Marque. We were having issues with this marker from Lab Vision, so we
switched to TTF-1 a while ago. We use the UltraVision LP detection kit from Lab Vision. It's a polymer driven detection kit. 

The antibody is a ready to use, and we have the time set at 30 minutes. 
 
We were getting the background staining on a liver specimen last week, and we also had this problem today on a lung case. My doctor is getting
frustrated, and wants me to do something about this, and to repeat the TTF-1 stain on the lung, so if someone can give me some suggestions to try, I'm
ready to try them.

Thanks in advance,
Paula
Lab Manager
Bio-Path Medical Group
Fountain Valley, CA