AW: [Histonet] overfixation with formalin

[Gudrun Lang]

Thank you Tony for this interesting „large-trial“ on tissue-fixation. And this also supports my opinion about formalin-concetrations.

The necessary modification of AR is certainly a point, why interlab-standardisation is a good point. 

Regards

Gudrun

 

Von: Tony Reilly [mailto:Tony_Reilly <@t> health.qld.gov.au] 
Gesendet: Donnerstag, 08. November 2012 00:20
An: 'gu.lang <@t> gmx.at'; Richard E. Edwards; histonet <@t> lists.utsouthwestern.edu
Betreff: RE: [Histonet] overfixation with formalin

 

Hello

 

I agree.  I recently saw presentation at a conference where a lab received specimens from Kiribati located in a small group of remote islands in the pacific.  They receive specimens in all sorts of solutions including sea water.  He was able to demonstrate good staining in specimens that had been in conc. 37% formaldehyde (no buffer) for 3 months simply by modifying antigen retrieval.  Of the 55 antibodies they stain in their lab there were only 2-3 where staining was not achieved.  But if they were underfixed!!!

 

regards

Tony

 

 

 

Tony Reilly  B.App.Sc. , M.Sc.

Chief Scientist, Anatomical Pathology

Pathology Queensland-PA Laboratory 

________________________________________________
Health Services Support Agency | Queensland Health

 

Level 1, Building 15,Princess Alexandra Hospital

Ipswich Road,WOOLLOONGABBA  Qld 4102
Ph: 07 3176 2412
Mob: 0402 139411

Fax: 07 3176 2930

Email: tony_reilly <@t> health.qld.gov.au

Web:  www.health.qld.gov.au/qhcss/

 

 



>>> "Edwards, Richard E." <ree3 <@t> leicester.ac.uk> 11/8/2012 1:38 am >>>
I have  seen far  more  damaged/unusable (apart from H <@t> E)   tissues through under-fixation than over-fixation.....................

-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu [mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Gudrun Lang
Sent: 03 November 2012 18:41
To: histonet <@t> lists.utsouthwestern.edu
Subject: [Histonet] overfixation with formalin

Hi histonetters!

I'm just attending a histo-course, where the teacher told us his opinion about overfixation.

For him overfixation takes place in any formaldehyde solution with a concentration above 5%. This should cause the margin-artefact, that leads to false-positive IHC at the margins of the tissue and to false-negative results in the center. The higher concetrated fixative should harden and shrink the surface, so it cant be penetrated any more by the fixative.



I told him about the publication of Cecil Fox, who saw shrinkage only in solutions with formaldehyde concentration above 30% (I think) and said, that the methanol-part is responsible for that.

I believe, that these margin-artefacts are due to drying at the time of biopsy or an effect of the needle-shot itself. (But believing is no
evidence)



In our lab we use 8% formaldehyde as standard fixative, buffered with low-molar phosphatebuffer. There are no complains from the doctors about margins.



Please help me with the histonet-wisdom. What's your opinion? 



Bye

Gudrun Lang



_______________________________________________
Histonet mailing list
Histonet <@t> lists.utsouthwestern.edu
http://lists.utsouthwestern.edu/mailman/listinfo/histonet

_______________________________________________
Histonet mailing list
Histonet <@t> lists.utsouthwestern.edu
http://lists.utsouthwestern.edu/mailman/listinfo/histonet

********************************************************************************

This email, including any attachments sent with it, is confidential and for the sole use of the intended recipient(s). This confidentiality is not waived or lost, if you receive it and you are not the intended recipient(s), or if it is transmitted/received in error.

Any unauthorised use, alteration, disclosure, distribution or review of this email is strictly prohibited. The information contained in this email, including any attachment sent with it, may be subject to a statutory duty of confidentiality if it relates to health service matters.

If you are not the intended recipient(s), or if you have received this email in error, you are asked to immediately notify the sender by telephone collect on Australia +61 1800 198 175 or by return email. You should also delete this email, and any copies, from your computer system network and destroy any hard copies produced.

If not an intended recipient of this email, you must not copy, distribute or take any action(s) that relies on it; any form of disclosure, modification, distribution and/or publication of this email is also prohibited.

Although Queensland Health takes all reasonable steps to ensure this email does not contain malicious software, Queensland Health does not accept responsibility for the consequences if any person's computer inadvertently suffers any disruption to services, loss of information, harm or is infected with a virus, other malicious computer programme or code that may occur as a consequence of receiving this email.

Unless stated otherwise, this email represents only the views of the sender and not the views of the Queensland Government.

**********************************************************************************