um, no. Deparaffinizing, dehydrating and then going back through paraffin is
too harsh on the tissue. For argument sake, try it out. I've been doing this
for years and haven't had a problem.
----- Original Message -----
To: "'Joe Nocito'" ; "'Lynn Wade'"
Sent: Monday, March 24, 2008 4:31 AM
Subject: RE: [Histonet] Reprocessing tissue
> Um no, Joe.....
> If you do that then the xylene/ wax impregnated tissue won't mix with the
> formalin (as you say), anyway it's fixed that's not the issue, so why
> time fixing again?. Melt the blocks down, as you say, then pass through
> xylem until they are transparent, well as transparent as the poor
> allows. You then place into 100% alcohol until properly dehydrated denoted
> by the xylene making them transparent (trial and error I'm afraid as you
> don't know how dehydrated they are). When clear impregnate with wax as
> before; you may note that the tissue becomes more brittle because of
> increased length of time in reagents and especially wax. But less so than
> Joe says as you are not doubling the processing time which must impact
> adversely on ICC.
> Have fun.
> -----Original Message-----
> From: email@example.com
> [mailto:firstname.lastname@example.org] On Behalf Of Joe Nocito
> Sent: 24 March 2008 00:46
> To: Lynn Wade; email@example.com
> Subject: Re: [Histonet] Reprocessing tissue
> ThermoFisher Scientific and Ventana Medical Systems have systems that you
> can barcode the paperwork, which then makes bar-coded blocks which then
> makes bar-coded slides. In each step, the barcodes are read to ensure that
> the correct specimen is being processed. If there is a mis-match, an alarm
> beeps alerting the user.
> For reprocessing tissue, we just melt the blocks down, place the tissue
> in the block and put the blocks in formalin to be processed with new
> Whatever area did not process the first time will take up the formalin,
> graded alcohols. When the tissues reach xylene, the paraffin is dissolved
> and everything get infiltrated. The areas that have been processed will
> repel the formalin and alcohols until they are immersed into xylene. I
> this method is a lot easier on the tissues, especially if IHC is performed
> on them later.
> As far a an electronically created list of blocks going into a processor,
> haven't heard of any.
> Hope this helps.
> ----- Original Message -----
> From: "Lynn Wade"
> Sent: Sunday, March 23, 2008 6:31 PM
> Subject: [Histonet] Reprocessing tissue
> Hi folks:
> I am wondering if anyone has had an incident in Patholgy lab where on the
> tissue processor the reagents got switched inadvertantly. For instance,
> 80% alcohol was inadvertantly placed in the last 100% alcohol slot and
> water was reintroduced into the tissue just before xylene, clearing amd
> Has anyone had this occur and how did you recover the tissue?
> Also, can anyone tell me if there is such a processor that has a system
> can be used to log in the cassette numbers that are put onto the processor
> so that in the event of some incident such as we had the retrieval of the
> exact specimens can be done electronically?
> And lastly can anyone tell me if they have a fully barcoded system whereby
> path specimens arrive barcoded and every document, slide and block has a
> barcode that allows for tracking of the tissue at all times?
> We are looking at processes and trying to close some gaps.
> Lynn Wade
> Program Manager, Safety & Quality Management
> Medical Services & Diagnostics
> Eastern Health
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