Fwd: Re: sectioning insects
|From:||"Dr. Ian Montgomery" |
hydrate, no problem, you can buy it from Merck (17.90 P Sterling) Use it
regularly for Mayer's (1903) haematoxylin.
Date: Wed, 27 Feb 2002 19:24:54
Dr. Ian Montgomery,
From: Tom Clarke <email@example.com>
Subject: Re: sectioning insects
To: Barry Rittman <firstname.lastname@example.org>
Cc: histology <email@example.com>
Thanks for the reply. I can probably get my hands on chloral
hydrate as we
have a vet school on campus and I think that drug is still used as an
anesthetic, though I suspect it will be a red-tape hassle. Do you
the chloral hydrate is necessary, (ie., can treating with phenol
same effect?) or if another chemical can substitute it? The
working on are late instar caterpillars, so the cuticle isn't overly
but still sufficently strong to cause problems in sectioning.
Barry Rittman wrote:
> Most of the experience I had sectioning insects was looking at
> dragonflies and dragonfly larvae almost 40 years ago but I did spend
> lot of time researching of methods to produce sections of the
> The most effective method I found was to concentrate on the
> itself. I mixed melt equal parts of chloral hydrate and phenol
> by gentle warming and used as the chitin softening agent (I cannot
> credit for this and chloral hydrate is probably difficult to get
> hydrate unless in business of shanghaiing sailors!)). This solution
> used after dehydration and specimens were left for up to a week in
> solution. Usually a day was adequate but did not hurt leaving
> longer. Then chloroform as an intermediary agent.
> Most of the other methods that I tried such as softening with
> did not seem to be effective.
> I think that effectiveness may depend largely on the insects and
> will not work with thick shelled coleoptera.
> Some of the older methods suggested snipping off a piece of the
> chitin to allow penetration of agents through the rest of the body
> An alternate is to use double embedding with celloidin-wax. Found
> work but not as well as first method.
> Yet another method was to use isopropyl alcohol dehydration in place
> ethanol dehydration to minimize hardening. Worked reasonably well
> larvae but was not as effective for adult dragonflies.
> If the insects have already been embedded I would recommend soaking
> block in water or using Mollifex.
> If the chitin tends to separate you might try to use the technique
> wiping a block of 45 degree wax over the surface before cutting
> section. Failing this (and probably by this time after several
> Guinesses)- try painting a thin layer of celloidin on the
> to dry and then cut the sections. This is time consuming but
> Effects on DNA - no idea?
> Tom Clarke wrote:
> > Does anyone have any experience sectioning paraffin embedded
> > Are there any methods that can be used to soften the chitin
> > significantly damaging the other tissues (in particular, the
> > -Tom Clarke-
> > Division of Biology
> > Kansas State University
Microscopy Service Unit,
Graham Kerr Building,
Institute of Biomedical & Life Sciences,
University of Glasgow,
Tel: 0141 332 8855
<< Previous Message | Next Message >>