I would check the level of the formalin after it has been pumped into the
retort.
I will wait till the pics are posted
Regards,
Tony Henwood MSc, BAppSc, GradDipSysAnalys, CT(ASC), FFSc(RCPA) (Retired)
Principal Scientist, the Children’s Hospital at Westmead (Retired)
Adjunct Fellow, School of Medicine, University of Western Sydney.
From: Verizon wireless via Histonet
Sent: Saturday, February 3, 2024 2:36:42 PM
To: histonet@lists.utsouthwestern.edu
Subject: [Histonet] Processing artifact - delayed start
Dear Histonet Members,
We have terrible processing artifact if tissue sits in the formalin-filled
retort (at ambient temperature) for too long (more than 10-12 hours) before a
delayed process starts. The longer the wait, the worse it looks. We have Tissue
Tek VIP 5 processors, and we process luminal gastrointestinal biopsies
exclusively. I've attached some photomicrographs of problem cases on the
Histonet Images website (with the same topic title).
This artifact typically affects a few specimens per day (~2% or less), even
though everything is done on the same processor; it may affect all tissue
portions in a cassette or only some of the tissue in that cassette. Some tissue
portions may only have the artifact on one half with the other half looking
perfectly fine. The techs sometimes note the tissue feeling "crunchy" at the
time of embedding and / or at the time of microtomy. These tissues tend to
suffer greater chatter artifact and have trouble sticking to the slides. The
sections look just as bad on recuts as the originals. Re-processing does not
seem to help at all.
If the cassettes sit in formalin in a container outside of the processor for
days before the processor is loaded (with subsequent immediate start), things
look perfectly fine. When we have staff around to start the processor
immediately upon loading cassettes and empty immediately upon completion, the
tissue looks perfectly fine.
Our current processing program is as follows:
1. 10% Formalin, 30 minutes, ambient temp, p/v on
2. 10% Formalin, 30 minutes, ambient temp, p/v on
3. 65% Alcohol, 10 minutes, ambient temp, p/v on4. 80% Alcohol, 10 minutes,
ambient temp, p/v on5. 95% Alcohol, 7 minutes, ambient temp, p/v on6. 95%
Alcohol, 7 minutes, ambient temp, p/v on 7. 100% Alcohol, 10 minutes, ambient
temp, p/v on
8. 100% Alcohol, 10 minutes, ambient temp, p/v on
9. Xylene, 15 minutes, ambient temp, p/v on
10. Xylene, 15 minutes, ambient temp, p/v on
11. Paraffin, 10 minutes, 60 degrees C, p/v on12. Paraffin, 10 minutes, 60
degrees C, p/v on13. Paraffin, 15 minutes, 60 degrees C, p/v on14. Paraffin, 15
minutes, 60 degrees C, p/v on
Obviously there are times we absolutely need to use delayed start. I would
greatly appreciate guidance, and I'll be happy to provide any other details
that might be useful.
Sincerely,
Brian Quigley MDLaboratory Director of a GI Pathology Laboratory
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