RE: [SPAM] [Histonet] reprocessing paraffin blocks

From:"Mickie Johnson"

Hi Everyone.  Thanks Gail for remembering my small article in Histo-Logic
about 5 years ago!

The procedure is very simple and the least harsh of any method I know. I did
not develop it, but one of my former students brought it back from NSH and
we used it with great success.

First, melt the block down and blot off the excess paraffin from the tissue.

Second, re-cassette the tissue in the same cassette, blotting excess
paraffin from the cassette.

Third, put the cassette in with the days normal tissue processing run, in

Fourth, process as usual.

The next morning, embed and cut. The fat (or under processed tissue will cut

The rational is that the well processed part of the block will have paraffin
in it and will not feel the effects of dehydration. Xylene will melt out the
paraffin and then paraffin will re-infiltrate this part.

The unprocessed tissue areas are available to fix additionally and
dehydrate, clear and infiltrate with paraffin. 

The net result is a reprocessed block with no harsh treatment and very
little time expended to 'reprocess' by hand. It does take overnight to get
the slides, but usually the pathologist will be happy to see slides he can
read accurately.

Hope this helps.

Good Luck!

Mickie Johnson, B.S., HTL(ASCP)
Mohs Histology Consulting Services, LLC
  & Mohs Lab Staffing
2507 S. Manito Blvd.
Spokane, WA 99203
Web: & 

-----Original Message-----
[] On Behalf Of Gayle Callis
Sent: Friday, May 04, 2007 9:18 AM
Subject: [SPAM] [Histonet] reprocessing paraffin blocks

Get this publication from Histo Logic on Sakura Finetek website.  It was 
very simple and very little work overall.

Technique for Correcting Poorly Processed Paraffin Blocks.
Michael L. Johnson, BS, HTL, HT(ASCP), Spokane, WA,  May 2003;XXXVI(1):21.

Gayle Callis
Research Histopathology Supervisor
Veterinary Molecular Biology
Montana State University - Bozeman
PO Box 173610
Bozeman MT 59717-3610

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