From: "Ronald M. Anderson"
Subject: Dissolving Araldite Summary
Thanks to all who quickly responded with excellent suggestions!
It's probably a sign of the times but I had no problem generating
a purchase requistion for the various sherrys suggested by Echlin
for process control. All I need are MSDS chemical hazard sheets
for them!
The following 300 or so lines summarize the responses with most headers
and footers removed:
..............................................................................................................................
Hi...I don't know if this will actually work for araldite but it works for
epon sections. You may want to try it on something you don't care about first
reference Maxwell, MH. 1978. Two simple and rapid methods used for the
removal of resins from 1.0 um thick epoxy sections. J. Microscopy 112, 253-255.
Prepare the following:
20 g KOH
100ml methanol
50 ml propylene oxide
reaction is exothermic, cool with ice.
after you prepare the mixture above, treat slides containing sections for
2-3 min, rinse in MeOH for 2 min, rinse in running water for about 2 min.
The slides are very difficult to wash clean.
good luck
I used this procedure for material which was embedded for EM which I then
wanted to stain and observe/photograph in LM. It seemed to work o.k. but the
epoxy was kind of difficult to remove and you need to keep observing the
sections to find out if, in fact, you had removed the
epoxy.
De Irving, USDA, WRRC, 800 Buchanan St, Albany, CA phone (510)559-5653
fax (510)559-5777
...............................................................................................................
The Epoxy Removal Kit marketed by Polysciences (cat. # 21487; $65.75; Fax:
1-800-343-3291) that is based on a published method (Stain Tech. 1990, 65:205),
might work.
M.V. Parthasarathy, E-mail: mvp2@cornell.edu
.............................................................................................................
I've used a solution we called 'ethoxide' (sodium hydroxide in
ethanol) to remove araldite from 2 micron thick sections. Don't
know if it'd work for larger volumes of polymerized epoxy.
--
Nancy L Desmond, Ph.D.
.....................................................................................................
We use the solution(s) reported by Maxwell
(Absolute Alcohol and Propylene oxide saturated with caustic, NaOH
or KOH) to remove small amounts of epoxy from the face of blocks. I
think we tried araldite once too and it worked. However, we've never
tried to completely dissolve a whole block and the sample you have
inside must obviously be able to resist the highly caustic solvent for
this method to be of any use.
Appropriate safety measures must be followed.
See: Maxwell, M.H. J. Microscopy 112(2):253-255 (1978).
Ladd Co. also used to make (and may still do) a solvent for cured
epoxy called Plastisolve. I've never used it though. I think most EM
supply companies carry some sort of solvent for cured resins.
Hope this helps.
Regards,
James Drummond, Pulp and Paper Research Institute of Canada
Vancouver, B.C.
.........................................................................................................................
From: DRK%SHCC.BITNET@cmsa.Berkeley.EDU
Hi Ron...Methylene Chloride (available as "Plastisolve" thru EMS) will do the
trick, given some time. Good luck!
.................................................................................................................
Sodium ethoxide will generally dissolve araldite. I'm sure there are
proper proportions somewhere, but I only know the bucket chemistry
version. Dissolve NaOH pellets in minimal water then mix with absolute
ethanol. It will usually darken over time. It works with metals such as
stainless steel, platinum etc. but I haven't used it with brass, copper
etc. If there is a fair amount of araldite present it may take a few days
to dissolve.
Best of luck,
Coral Gilkeson
............................................................................................................
A solvent for Araldite is DMF (or Dimethyl Formamide I think) This will at
least soften it. Be careful as this is suspected carcinogen and has been
linked to testicular cancer.
Richard Thornton
email: r.thornton@trl.oz.au
........................................................................................................................
Perhaps this one is well known to all those currently doing biological
microscopy - but I remember way back when I was doing bio - we dissolved Epon
using Sodium Ethanoate - which was made my adding NaOH pellets to absolute EtOH
- the mixture had to age for several days in a light tight bottle to be
effective - tried it recently to (successfully) remove the sizing from
fiberglass that is added polymer parts.
Good Luck
Dave Calvert
Eastman Chemical Co
.
Kingsport, TN
......................................................................................................
Use either sodium methoxide or sodium ethoxide. These can be made by
making a saturated solution of sodium hydroxide in either 100% ethanol or
methanol. It takes a little time to mature and you end up with a sherry
coloured liquid. By sherry colour I mean a fino not an amontillado or an
oloroso ! When using, dilute 1:1 in either EtOH or MeOH. It's powerful
stuff so use with caution.
Best wishes for the holiday season
Patrick Echlin
..............................................................................................
I have a lot of long stories like this myself.
I've taken cured epoxy blocks and de-epoxied using a kit designed to work
on slides. Electron Microscopy Sciences has a "Cured-Epoxy Remover" kit,
Cat 14942. EMS can be reached at:1-800-523-5874.
I trim around the object , trimming off as much epoxy as possible,
when necessary using a vice and little saw.
Then I allow the parts to soak in the etching solution A, using a couple of
rinses, for as long as it takes to take all visable traces of the epoxy
away. This may be 2-5 hours. Then go througn the rest of the procedure,
lengthening the steps up to but not including dehydration. The protocol
sent is actually for thick section slides, and asks for only 2-5 minutes
per step. I've done this twice with biological tissue, and the results
were amazingly and unexpectedly nice.
Hope this helps,
Lou Ann Miller
College of Vet Med
University of Illinois
217-244-1566
=========================================
Some time ago I use a concentrated Sodium hydroxide solution disolved in pure
propylene oxide for removing Araldite from thin slices of biolgical material.
It may work with your stuff after treaming down the excess Araldite from around
the parts. The solution is nasty, use with caution.
*Cesar D. Fermin, Ph.D Fermin@TMC.Tulane.edu -***
...........................................................................................................
"Gentle, Consistant and Rapid Solvation of Araldite or Epon from
2um Thick Sections" Daniel Hogan, Gilbert Smith. Laboratory of
Molecular Biology, NCI NIH, Betheda, MD 20205.
I don't have the full citation, but I do have a copy of the one
page article (photocopy which cut off the journal name etc.).
Their solvent solution, which works but you have to keep an eye
on it for larger samples - I've used it with emmbedded samples cut to
reveal desired structures and then de-emmbeded for SEM.
Equal volumes of 0.5% KOH, absolute Methanol, Benzene and
Acetone. Rinse samples with Methanol.
For larger samples I've found placing the blocks on screen
supports in a beaker with a magnetic stirring bar and the solvent
solution works.
Good luck.v
Richard E. Edelmann
Electron Microscopy Facility Supervisor
Marshall University - School of Medicine
Huntington, West Virginia
=========================================
If it won't hurt the parts, try straight propylene oxide. When I was
young and stupid (1967) I embedded a few V-nickels and buffalo head
nickels in araldite. Just recently I put the nickels in propylene oxide
overnight and the next day the araldite had dissolved. I did another
couple of changes over a 20 min(approx. time span) period to make sure I
got all of the araldite off. Hope this helps.
From: Philip Oshel
...................................................................................................
Ron Anderson,
I've used acetone to dissolve epon & such like plastics from biological
specimens. Your problem may require mild warming and/or sonication.
*This is NOT intended as a snide remark!* Have you tried potting things in
Sylgard (Du Pont) aka sylastic, a silicone elastomer? Clear, and can be
cut away from the potted whatever. perserving the mold for casting or...
Phil Oshel
poshel@luc.edu
=====================================
n,
A company called Dynaloy, Inc. makes a series of depotting solvents intended
for the industrial and electronics markets. We have had good luck using them
in a number of cases requiring dissolution of epoxy (including a straining
stage entombed in epoxy by an over eager user attempting to epoxy his sample
directly to the jaws of the stage!). Good luck.
Dynaloy, Inc., 7 Great Meadow Lane, Hanover, NJ 07936,
201-887-9270, 201-887-3678 (fax)
-------------------------------
| Frank J. Scheltens |
| scheltfj@ml.wpafb.af.mil |
.................................................................................................................
Well, I once dissolved LX-112 (Epon) from some small, ciliated specimens
by PROLONGED (weeks) soaking in propylene oxide. But I think one of the
two problems I was trying to remedy was that the resin wasn't *completely*
polymerized. Chip away as much as you can and go at it. I'll be
interested in hearing any other solutions people recommend! I'm also
curious as to what your samples were - we all like to hear that we aren't
the only ones who make dumb moves!
Tina Weatherby Carvalho
=============================
From: Supratik_Guha@mail.mmmg.com (SG)
Try immersing in boiling H2SO4 at 160-170 degrees C. This is how I get
LED epoxies off to get at the emitter. Seems to work very nicely. The
H2SO4 has to be really very hot though.
..................................................................................................................
>From Hans Ris, hris@facstaff.wisc.edu,
Integrated Microscopy Resource,
University of Wisconsin, Madison, WI. USA.
Walt Bobrowski and Sverker Enestrom commented recently on epon extraction
for LM and Immunogold labelling using sodium ethoxide. Sodium or Potassium
ethoxide or methoxide have been used in the past to remove epon from blocks
or sections for LM cytochemistry or SEM imaging. Experience has shown that
these agents are inefficient and highly destructive for cell structures.
In 1990 Iwadare et al, Stain Technol.65,205-209, published an improved
and less destructive protocol for LM cytochemistry and immunolabelling
(crown ether complex). Dr Marek Malecki and I have explored this new
technique for high resolution SEM imaging of thick epon sections after epon
removal. The results have been published in the Journal of Structural Biology
111, 148-157(1993). This new technique preserves nanometer structures in the
nuclear pore complex and insect flight muscle. After extraction of the epon
immunolabelling of actin, myosin and alpha-actinin was successful. The
extraction solution is commercially available. Source and details of
procedures are described in the J.Struct.Biol. 111,148 (1993) paper by
Ris and Malecki.
[ Return to Tips & Tricks Menu]