Dear Kathleen:

All of our harderning problems have been due to overdehydration. Here's
our overnight protocol and it works wonders for most tissues, including
rodents:

1.10%formalin-4hours
2.70%ethanol-50'
3.80%ethanol-50'
4.95%ethanol-45'
5.95%eth.-55'
6.100%eth.-45'
7.100%eth.-55'
8.xylenes-45'
9.xylenes-55'
10.paraffin-40'at 59degrees x3times

Our retort temperature is set at 34 degrees and our oven at 60 degrees.

You may call me or write if you have any questions.

Good luck in the name of our profession.

Milton

-----Original Message-----
From: Kathleen Roberts [mailto:kgrobert@rci.rutgers.edu]
Sent: Tuesday, August 12, 2003 10:32 PM
To: HistoNet@pathology.swmed.edu
Subject: Tissue processing problems


To all-

We are a small university pathology lab that does mostly rodent and some

fish tissues, and lately they have been coming out of the processor hard

as a rock and very difficult to cut, and we have been trying to figure
out what, if anything, we are doing wrong.  We have tried changing out
the reagents more often, but it doesn't seem to have made a difference.
We doubt that it's the temperature of the paraffin, as our settings are
in agreement with the manufacturer's recommendations, and the
temperature displayed agrees with our thermometer. Could you please send

me your processing protocols for comparison?

If you like, I will send you our protocol as well.  Any and all ideas
and suggestions will be very welcome.

Thanks in advance for your help-
Kathleen Roberts
Principal Lab Technician
Neurotoxicology Laboratories
Molecular Pathology Facility Core
Dept of Pharmacology & Toxicology
Ernest Mario School of Pharmacy
Rutgers University
41 B Gordon Rd
Piscataway, NJ 08854
(732) 445-6914
FAX (732) 445-6905