Re: Jellyfish for SEM

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From:"R.Wadley" <>
To:Scott Whittaker <>
Date:Fri, 13 Aug 1999 09:58:13 +1000
Content-Type:text/plain; charset="us-ascii"

	Dear Scott,

	I've never had to work on a botanical sample, but they seem to throw up
all sorts of weird & wonderful challenges.

	The resin infiltration idea is one I have been kicking around for a while,
but never had the oportunity to really put it to the test.  The theory is
you use a hyrdophilic resin for infiltration, thats easy, then for
polymerisation you have to get the resin to 'go off' while preventing it
creating a film of the surface of your specimen.  Obviously the integrity &
dynamics of the specimen surface play a big part in how successful this
method is.  I would imagine the top (head?) of the jelly fish could be well
presented this way, but the more ruffled under structure & vibrio could be
difficult.  Ideally the resin would set at room temperature so it was
comfortable to work with.  

	JB4 could be good because it doesn't polymerise well in the presence of
oxygen.  This means the resin in the centre of the jellyfish polymerises
but the stuff on the surface of the specimen can be removed (by wiping,
mopping or washing) & polymeristaion completed uder vacuum.  Result:  A
preserved specimen fully demonstraing all its surface characteristics.

	I really don't know what to expect with freezing of a jellyfish.  I have
recently been involved in X-ray analysis of frozen chicken eyes.  One of
the real problems was rapid freezing of such a relatively large object that
is in reality smaller than this jellyfish.  I suspect that even after a
full fixation regiem (including glut., OsO4, & even U'acetate) that the act
of freezing would shatter the body of the j'fish. 

At 08:34 08/12/1999 +0100, you wrote:
>All sound good as well provided they have the equipment.  Replica is a
>quick and easy idea.  Not too fond of the resin idea, but as I have never
>tried it can't say it wouldn't work either.  Wouldn't you just be imaging
>the resin. SEM is monochromatic, imaging the sputtered heavy metal surface
>and is seems the tissue and the resin would be indistinguishable.  I just
>based the reply on my work with the "goo" in  tomatos. Standard fixation
>and osmocation was the only thing which worked with a wet fracture from
>ethanol/LN2. What a nightmare that was on the overripe samples though. 

R. Wadley, B.App.Sc. M.L.S, Grad.Dip.Sc.MM
Laboratory Manager
Cellular Analysis Facility
School of Microbiology & Immunology
UNSW, New South Wales, Australia, 2052
Ph (BH) 	+61 (2) 9385 3517
Ph (AH)	+61 (2) 9555 1239
Fax 	+61 (2) 9385 1591

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