[Histonet] RE: Microwave Processors

[Mayer,Toysha N]

Tim is right, fixation is the key to microwave processing.  Size of the tissue is very important for fixation, so be aware of that as well.  Once you work out the times per change of reagent the tissues should be just fine.  To avoid being concerned about the melted paraffin, invest in a paraffin tank.  You know like the big coffee pot dispensers.  It will be well worth it in the end. 
One other thing is to make sure when you dispose of the alcohol that you do not accidentally get water on the tissue.  I used to pour the alcohol down the drain (before we had to put it in a waste container) and would wash it down with water, let's just say the tissue got water on them and the results were bad.   
MW are good for same day biopsies because they can shorten the TAT.  It works great for GI bx.

Sincerely,

Toysha N. Mayer, MBA, HT(ASCP)
tnmayer <@t> mdanderson.org
Instructor/Education Coordinator
Program in Histotechnology
School of Health Professions
MD Anderson Cancer Center
713-563.3481

Message: 8
Date: Fri, 27 Sep 2013 22:12:06 +0000
From: "Morken, Timothy" <Timothy.Morken <@t> ucsfmedctr.org>
Subject: [Histonet] RE: Microwave Processors
To: "Dubansky, Benjamin" <Benjamin.Dubansky <@t> unt.edu>,
	"histonet <@t> lists.utsouthwestern.edu"
	<histonet <@t> lists.utsouthwestern.edu>
Message-ID: <761E2B5697F795489C8710BCC72141FF09B9E2 <@t> ex07.net.ucsf.edu>
Content-Type: text/plain; charset=us-ascii

Ben, we used a Thermo Histowave II (made by Electron Beam Sciences) for many years for rush transplant biopsies. It worked Ok and the results were about 90% of the quality of regularly-processed tissue - however  I think the slightly lessened quality was the shorter fixation time the bx had - maybe 2 hours from excision to starting processing.  We did not do formalin fixation in the MW processor. 

The MW tissue processor part took about 15 minutes and required several manual changes of solutions, so was in a fume hood. It was more of a hassle to keep melted paraffin around than to run the processor. We kept the MW containers and paraffin ready in a dedicated oven. We used it daily so it was routine. 

The thing finally died and we now use a Peloris processor for Rush bx. The results are similar. Again, probably due to short fixation.

MW processing should not be any scarier than any other processing.  It simply requires validation, in which you define the results you expect and then work towards that in the workup.


Tim Morken
Supervisor, Electron Microscopy/Neuromuscular Special Studies Department of Pathology UC San Francisco Medical Center



-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu [mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Dubansky, Benjamin
Sent: Friday, September 27, 2013 1:51 PM
To: histonet <@t> lists.utsouthwestern.edu
Subject: [Histonet] Microwave Processors

Can some of you weigh in on how you feel about microwave histoprocessors?  I am terrified that my samples will end up like raisins.  "They" swear that these milestone processors are just as good as any other method, in terms of quality.  I'ts all I have right now and it is very tempting to use it, although I am considering doing things the old fashioned way.  And I am talking about pre-processor old fashioned way.  I am that scared.

Ben

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End of Histonet Digest, Vol 118, Issue 48
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