RE: [Histonet] richard-allen type 9 paraffin

From:"Hugh Luk"


Just my 2 cents.  If any of this helps, great.

I've found this is one of the hardest, polymer-rich paraffins available.  I 
find it similar to Surgipath's standard embedding paraffin and Cardinal's 
(old S/P) Ameraffin.  It sections and ribbons well. Currently, however, I am 
using Ameraffin (also made by Richard Allan), which I find very 
interchangable with type 9.

We modified our tissue processing (a little more time in wax-multiple 
changes totalling around 2 hours at 58 to 62C- and maybe more alcohol), 
deparaffinization (more time in solvent), and two, different microtome 
blades.  Sakura's Accu-Edge HIGH profile blades are honed perfectly to cut 
ANYTHING at 4 microns with this wax.  The "Slight compression" is balanced 
with "Ease of ribboning."  We sometimes use a wider angle on the blade 
holder to increase the rake angle.

For really thin sections, "Sharper" blades (like Duraedge, Leica's, or 
Richard Allan's blades) are required.  For example, on delicate biopsies and 
lymph nodes, 1 or 2 microns is no problem!  I also like the way the paraffin 
holds its shape on the water bath (~38-44C).

I learned histology using Paraplast X-tra.  I've tried Paraplast, Paraplast 
plus (with DMSO), Fisher Tissue Prep and Tissue Prep2 embedding medias.  
When we had a new supervisor at QMC, she changed the paraffin to a harder 
wax.  We complained about it because it felt different, but I came to really 
like it.  It became my standard where ever I work (thanks Jackie O').

If you are experimenting, you will need to do full switch-overs, every 
instrument using wax should be changed.  Mixing paraffins of different 
grades is cheating the experiment.

My conclusion is they are all pretty good.  The paraffin is only for 
support; and with a little tinkering, I like to think I can use any one of 
them at any time.

Hugh Luk, HTL (ASCP)
Former histopathology supervisor CLH
Cancer Research Center of Hawaii
1236 Lauhala Street, Room 316
Honolulu, HI  96813
Tel: (808) 440-5238
Fax: (808) 586-2982

>Subject: [Histonet] richard-allen type 9 paraffin
>Date: Wed, 23 Feb 2005 17:42:03 EST
>Hello everyone,
>The lab that I work for recently decided to switch to Richard-Allen type  9
>paraffin.  I was wondering if anyone has experience with this  paraffin and
>could give some advice on techniques used in cutting it.   Opinions of this
>product would also be greatly appreciated.
>Thanks in advance,
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