Hello Jeremy:
 
My lab does extensive histology work on mollusks, mostly eastern oyster and
various species of clams.  We use Davidson's fixative for probably 90% of
the samples.  Davidson's formula is as follows:
 
37-40% formaldehyde solution    200ml
95% ethanol                              300ml
glacial acetic acid                      100 ml
isotonic artificial seawater           300ml
glycerin                                     100ml
 
BL Shaw and HI Battle. 1957.  The gross and microscopic anatomy of the
digestive tract of the oyster Crassostrea virginica Gmelin. Canadian Journal
of Zoology 35:325-347.
 
We find that eliminating the glycerin has no deleterious effect on fixation
(and actually increases the relative concentration of the ingredients with
fixative properties).  It only function seems to be as a 'softening' agent.
You may find it helpful with tough abalone tissue.  Our protocol calls for
48hr fixation at room temperature at 15-20 fixative:tissue ratio.  Gentle
agitation improves fixative penetration.  Tissues must be cut at 3-5mm in
thickness.  Send me your address and I will send you our processing schedule
for mollusk tissues.
Here are direct references to Davidson's as described on Bob Richmond's web
page:

"REFERENCES: Davidson's fixative is not mentioned in most standard reference
works on histology. It is named after William McKay Davidson, a British
hematologist, and was publicized by Moore and Barr in their well-known
studies of sex chromatin. Davidson's fixative is often called Hartmann's
fixative because of its introduction by Dr. William H. Hartmann (later at
Vanderbilt) while he was at Johns Hopkins.

Moore KL, Graham MA, and Barr ML. "The detection of chromosomal sex in
hermaphrodites from a skin biopsy." Surgery, Gynecology and Obstetrics
1953;96:641-648. 

Moore KL and Barr ML. "Nuclear morphology, according to sex, in human
tissues." Acta Anatomica 1954;21:197-208. 

Procedure written by Robert S. Richmond, M.D., F.C.A.P., July 1997."

Cited from http://members.aol.com/rsrichmond/histology.html. Retrieved from
Internet 6-21-99 by CBM. 

 

I have looked up several papers on disease and microanatomy of abalone in
the Journal of Shellfish Research.  One used Bouin's, which I wouldn't
recommend for safety and histological reasons (can't get rid of it and it
destroys DNA), and one used 10%NBF.  You may want to do a more extensive
literature search on abalone disease, looking for techniques.  Try Elston &
Lockwood 1983 J. Fish Diseases 6:111-128; Friedman 1991 Journal of Shellfish
Research 10:236; Bower 1987  Canadian Journal of Zoology 65:1996-2007,
2008-2012, 2013-2020; and various papers by Lester, RJG.

Hope this helps.

Regards-

Carol
*********************
Carol B. McCollough, HT/HTL(ASCP)
Diagnostics & Histology Laboratory Manager
Maryland Department of Natural Resources
Cooperative Oxford Laboratory
904 S. Morris Street
Oxford, Maryland 21654
cmccollough@dnr.state.md.us


 
 

-----Original Message-----
From: Jeremy Papier [mailto:jeremy@pathcare.co.za]
Sent: Monday, May 06, 2002 10:27 AM
To: HistoNet@pathology.swmed.edu
Subject: Abalone


Dear All
 
We are required to prepare blocks and ultimately sections on Abalone for a
research project.Can anyone please recommend any information as to fixatives
and processing procedures.Davidson's fixative has been mentioned - is anyone
familiar with this.
 
Thanks
Jeremy  Papier
Pathcare 
 
 
 
 

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