[Histonet] Processing Schedule- ASP-6025

Greg Dobbin greg.dobbin at gmail.com
Tue May 7 14:07:08 CDT 2019

Hello  colleagues,
I recently stained (IHC) a section of normal tonsil from another facility
with p16 and the resulting stain was better than the same stain on a
section of my labs own normal tonsil control.

This has led us to question our processing schedule. I am not concerned
with our fixation because we fix everything for at least 24 hours in 10%
formalin (commercially prepared) prior to processing.

Does anything jump out at you as being a potential red flag in the
following overnight protocol?

   - Formalin 15 mins; RT
   - Processing water 1 min; RT
   - ETOH 70% 30 mins; 35C
   - ETOH 80% 30 mins; 35C
   - ETOH 95% 30 mins; 35C
   - ETOH 100% 30 mins; 35C
   - ETOH 100% 40 mins; 35C
   - ETOH 100% 60 mins; 35C
   - Xylene  60 mins; 35C
   - Xylene  60 mins; 35C
   - Xylene  60 mins; 35C
   - Paraffin 60 mins; 57C; vacuum
   - Paraffin 60 mins; 57C; vacuum
   - Paraffin 60 mins; 57C; vacuum

Our formalin is changed after every 1100 cassettes and the alcohol, xylenes
and paraffins are managed similarly by the instrument. Our specimen mix is
a little of everything (skins, GIs, breasts, needle cores, gall bladders,
gyne, etc).

The one unknown (so far) in this story, is how the tonsil from the other
laboratory was handled (ie the fixative used and for how long-I am assuming
10% formalin).

Obviously, many of you will have schedules that differ from this one, in
any number of ways, but what I am looking for from you is your opinion: *is
there anything about this schedule that is particularly concerning?*
Thank you,

*Greg Dobbin*
1205 Pleasant Grove Rd
RR#2 York,
PE      C0A 1P0

*Everything in moderation...even moderation itself**!*

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