[Histonet] Extended time in paraffin

Weems, Joyce JWEEMS <@t> sjha.org
Fri Feb 23 12:55:56 CST 2007

I believe this has to do with the new FDA ruling rather than "overfixing" as we think of it. It just has to do with standardization. j

-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu
[mailto:histonet-bounces <@t> lists.utsouthwestern.edu]On Behalf Of Bryan
Sent: Friday, February 23, 2007 1:29 PM
To: Monfils, Paul; histonet <@t> lists.utsouthwestern.edu
Subject: Re: [Histonet] Extended time in paraffin


Ahh! the voice of reason!
No kidding, even 5-7 days or more won't 'overfix' because there is NO such 
thing as 'overfixation' in NBF.


----- Original Message ----- 
From: "Monfils, Paul" <PMonfils <@t> Lifespan.org>
To: <histonet <@t> lists.utsouthwestern.edu>
Sent: Friday, February 23, 2007 1:18 PM
Subject: RE: [Histonet] Extended time in paraffin

Personally I don't believe that a couple of days in formalin will "overfix" 
anything, and large fatty tissues like breast and colon specimens can only 
benefit from additional fixation time. That having been said, if you do want 
to limit the fixation time, why don't you program the processor to keep the 
tissue in the fixative in station 1 for the desired length of time, then go 
into an extended 70% ethanol in station 2, where the tissue can be held 
safely for as long as necessary before proceeding into 95% ethanol and the 
rest of the cycle on sunday night as usual.

> ----------
> From: histonet-bounces <@t> lists.utsouthwestern.edu on behalf of Theresa Rohr
> Sent: Friday, February 23, 2007 8:14 AM
> To: Histonet <@t> lists.utsouthwestern.edu
> Subject: [Histonet] Extended time in paraffin
> I have a problem with processing breast tissue over a weekend. Breast 
> tissue is run in a separate processor from our Sugical and endo specimens. 
> We do not have weekend staff. We usually run a two day delay with the 
> processing starting Sunday night and both processors ending early Monday 
> AM.
> The current guidelines suggest this delay of breast tissue sitting in 
> formalin could result in over fixed breast tissue.  The pathologists want 
> to end the cycle on Saturday but we have no staff here to remove and/or 
> embed the tissue. The pathologists themselves would have to remove the 
> cassettes from the paraffin!
> The questions are what can they do with these cassettes? Again, the tissue 
> is breast tissue, mainly cores or target blocks or tumor that may need IHC 
> and/or FISH on diagnosis
> 1.  Can they just leave the cassettes on the processor in warm paraffin 
> (60 degrees) from Saturday until Monday?
> 2.  Can they remove them from the paraffin and let them harden at room 
> temperature and then be heated, melted and properly embedded on Monday?
> 3.  Can they put the cassettes in a container of warm paraffin "to cover" 
> and then let the whole container solidify and on Monday Histo melts the 
> container, removes the cassettes and embeds?
>  I have only found two clear commentaries.
>  Sheehan and Hrapchak who say extended time in paraffin will cause 
> shrinkage and hardening. There is also a reference in Carson, saying 
> tissue should remain in paraffin the shortest time necessary for good 
> infiltration as prolonged heat causes shrinkage and hardening.
> Can any of you offer me any further references and/or assistance or your 
> own methods/experiences?
> Thank you so much for your time and assistance
> Theresa Rohr
> Nyack Hospital, NY
> rohrt <@t> nyackhospital.org
> Theresa Rohr, BA, HT(ASCP)
> Section Head, Histology
> Nyack Hospital
> 160 North Midland Avenue
> Nyack, New York 10960
> phone 845-348-2276
> fax 845-348-8430
> Nyack Hospital is required by Law to protect the privacy of health 
> information under HIPAA Rules and Regulations Part 11, Article 45 CFR, 
> Parts 160-164. This email, including attachments, is intended for the 
> exclusive use of the person or the entity to which it is addressed. It may 
> contain confidential or legally protected information. The authorized 
> recipient is prohibited from disclosing this information to any other 
> party and is required to destroy this information after its stated need 
> has been fulfilled. If the recipient or reader of this email is not the 
> intended recipient or her/his authorized agent, the reader is hereby 
> notified that any dissemination, distribution or copying of this email is 
> prohibited. If you believe that you have received this email in error, 
> please advise the sender immediately by reply email and then delete this 
> email immediately.
>  >
> _______________________________________________
> Histonet mailing list
> Histonet <@t> lists.utsouthwestern.edu
> http://lists.utsouthwestern.edu/mailman/listinfo/histonet
Histonet mailing list
Histonet <@t> lists.utsouthwestern.edu

Histonet mailing list
Histonet <@t> lists.utsouthwestern.edu

Confidentiality Notice ** The information contained in this message may be privileged and is confidential information intended for the use of the addressee listed above. If you are neither the intended recipient nor the employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any disclosure, copying, distribution or the taking of any action in reliance on the contents of this information is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer. Thank you. Saint Joseph's Health System, Inc.

More information about the Histonet mailing list