Harder paraffin for bone samples

From:Gayle Callis

We always use Tissue Prep 2 from Fisher for both infiltration and
embedding, although another paraffin could be used for infiltration as long
as you embed in Tissue Prep 2.  We  processed large bones with extended
schedule using a SAKURA-FINETEK VIP with alternating vacuum/pressure - it
is important to use vacuum with hand processing particularly for paraffin
infiltration.  Not too difficult with hand vacuum pumps, vacuum dessicators
and heated, vacuum ovens - hopefully you have some of these gadgets. 

To improve sectioning of your large bone section, two ways of doing this: 

Use xylene for the first change of clearant, and either Propar (ANATECH) or
Clearite 3 (Richard Allan) for the second clearing change.  This prevent
hardening by the xylene, but removes the water (xylene is less sensitive to
water, removes it very well) and restores the color of the bone to some
degree but Propar or Clearite 3 don't harden decalcified bone excessively.  

You need to change your knife blade very frequently, hopefully you are
using a c profile steel knife. Even a tungsten carbide c profile knife can
help with large sections. 

A good friend and excellent bone hisotech always used a tape transfer
technic (a 3M (3750G) shipping tape for every section, never missed one!)
and tranferred large bone sections to a huge glass slide.  This keeps the
large section from curling, being a proverbial pain.  Diane Sterchis's tape
technic is found in J of Histotechnology, 1998 or so and she cut some HUGE
bones with a polycut/sledge microtome. This method is easy to use with
gigantic bone samples. 

Good luck

At 08:56 AM 11/7/02 -0500, you wrote:
>I work in an orthopedics bone lab and am trying different paraffins to
>infiltrate and embed in to be able to cut good sections.   I am currently
>using Fisher' paraplast x-tra.  I tried using Richard-Allan's Type 9 and I
>am having problems.  I manually  process  large pieces of bone that are
>about 5 mm. in thickness and fit on a 5" x 7'' slide. I should mention I
>clear with xylene.  Can anyone recommend a paraffin  that would make cutting
>bone sections easier?  
>I would appreciate your help.
>Peggy DiCarlo HT (ASCP)
>Buffalo General Hospital
Gayle Callis
Research Histopathology Supervisor
Veterinary Molecular Biology - Marsh Lab
Montana State University - Bozeman
S. 19th and Lincoln St
Bozeman MT 59717-3610

406 994-6367 (lab with voice mail)
406 994-4303 (FAX)

email: gcallis@montana.edu

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