[Histonet] RE: Cassettes and Processing and Fixation ~ Oh My!

[Stancel, Barbara]

Laura,

1.  In the past we used different colored cassettes for rush, non rush
and special projects. Then we noticed that we still treated every case
like it was retained/rush!! So we dropped back to one color for all our
regular cases; microscreen cassettes for anything that might slip
through and for our comminuted meat products. 

2. Day (3 hours) run blocks are "dumped" in (i.e. not organized).  We
don't usually have any problems except with the tissues cut by one
pathologist - who cuts too fast and sometimes too thick. But since I am
here alone in the wee hours of the mornings to embed, I prefer my night
(16 hrs run) blocks organized in neat 20 block rows and a lid placed on
the basket. Our baskets do not have organizing spacers. We pack'em tight
for long overnight runs! We have never had infiltration problems with
them.  We use pressure/vacuum (both VIP  E300s) on all stations, all
runs.

3. Our tissues are shipped overnight. So 99% of them are received nicely
fixed. Exception: winter time-and tissues being shipped from the
Northern states and Canada.  If they are received in formalin and are
under-fixed, after grossing, we transfer them to warm formalin until
they go on the processor, then we give them 10 minutes on the processor
with heat/vacuum/ pressure. All tissues arriving after 10 AM are held
for overnight. Approximately 50% of cases are completed and diagnosis
reported in 8-9 hours after arrival. The next 45% are completed in 24
hrs. The last 5% are completed within 72 hours from arrival.  We started
cay runs in 1978. We used an Ultra AutoTechnicon (with an agitating
basket) followed several years later by the Fisher Histomatic (with an
adjustable-speed stir bar in the bottom of the chamber):both  processors
had a direct method of stirring.  We were able to process tissues in 2
hrs. When we began our search for a new processor in the 1990's, there
were no processors with a stirring bar in the bottom of the processing
chamber-our processing times increased to compensate for reduced
agitation. 

Good luck in your quest to shorten processing and turn-around times. We
have all struggled with the same questions. And through trial-and-error
(or trial-by-fire!) ultimately found the times right for each lab's
unique circumstances and problems. 

Histologically yours,
Barbara
Barbara Stancel, HTL(ASCP)
Lead Technologist
USDA, FSIS, EL, Pathology 
RRC, 950 College Station Road
Athens, Georgia 30605
706-546-3698  or  706-546-3556
barbara.stancel <@t> fsis.usda.gov

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