[Histonet] Re: horseshoe crabs

[Stephanie Weaver]

I have no experience with horseshoe crabs, but we do process many aquatic animal specimens.  We have used Davidson's fixative (acetic-alcohol-formalin) to soften the exoskeleton.  Post-fixation after 10% NBF works as well, since many of our clients do not have anything but formalin on hand.  I'm not sure how well it would work on something as large and solid as a horseshoe crab, but we have had success with fish, shrimp, and hermit crabs.

Stephanie Weaver
Texas Veterinary Medical Diagnostic Laboratory

Message: 10
Date: Thu, 28 May 2009 10:56:10 +0100
From: Deborah Faichney <d.a.faichney <@t> stir.ac.uk>
Subject: [Histonet] Horseshoe crab..help!
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Hi all,

I have a Masters student here who has Horseshoe crab tissues fixed in 10% NBF.  Most of the tissues have been sectioned successfully but the eyes are surrounded by armour plated chitin! (she broke two Dremel drills trying to cut the carapace and finally tin snips had to be used to cut them out!!).
Any thoughts on how to soften them?  Looking around on the Net, I have found  that processing and clearing through Chloroform may soften, also a solution called Diaphanol has been recommended.
At the moment they have been two days in a 1 part acetic acid to 5 parts NBF with no effect.
We only have a couple of weeks to do this work so cannot adopt any trial or lengthy methods.

Is this possible?  I like a challenge, but suspect this needs a miracle.  Its no wonder these beasties have been on the planet for so long.
Many thanks

Debbie Faichney
Histopathology
Institute of Aquaculture
University of Stirling
Stirling, FK7 7QS
Scotland
Uk