[NHCOLL-L:4599] Re: Use of isopropyl for fixing and storing invertebrates
A.J.van_Dam at lumc.nl
A.J.van_Dam at lumc.nl
Sat Nov 7 04:42:19 EST 2009
Especially for monitoring the isopropanol concentration, the Alcomon 4 indicator has been developed. Shifting point 40% IPA. For requesting a free sample go to:
http://alcomon.com/contact.php
Since the new product is not yet presented on the company's website don't forget to specify your request (sample Alcomon 4).
Best regards,
Andries J. van Dam, conservator
Associate scientist
Natural History Museum, London
Directory Board member ICOM-CC
http://www.icom-cc.org
Director Alcomon Company
http://www.alcomon.com
Museum of Anatomy
Leiden University Medical Center
Postal zone T7-P
P.O. Box 9600
2300 RC Leiden
The Netherlands
tel: +31 (0)71 526 9581
fax: +31 (0)71 526 8275
E-mail: A.J.van_Dam at lumc.nl
Visiting address: Hippocratespad 21, building 3
-----Oorspronkelijk bericht-----
Van: owner-nhcoll-l at lists.yale.edu namens H.J. Walker
Verzonden: vr 6-11-2009 22:16
Aan: simmons.johne at gmail.com
CC: amsnyder at unm.edu; nhcoll-l at lists.yale.edu; ryan.evans at ky.gov; brian.lang at state.nm.us
Onderwerp: [NHCOLL-L:4598] Re: Use of isopropyl for fixing and storing invertebrates
Hello All,
Part of Ryan's plan, which John did not address, is fixation in
isopropanol and neither alcohol should be used as a fixative. However,
if formaldehyde is not available, high concentrations of ethanol (ca 70%
or greater) have been used. I agree with John in questioning the need
to buffer the alcohol.
John does a fine job explaining the isopropanol/ethanol comparison for
preservation, but for fishes there are millions of specimens preserved
for 65 years or more in isopropanol and many of the detracting
characteristics mentioned below are negligible for most scientific
purposes. Rather than a point-by-point discussion, it should be noted,
for example, that studies have been conducted showing more shrinkage in
ethanol, and those millions of specimens (above) have not cleared in
concentrations of 45% isopropanol. (50% is more than adequate for
fishes.)
Best wishes,
H.J.
John E Simmons wrote:
> Lex and Ryan
> Isopropyl can be used as a preservative,but be aware that it has
> problems. I have inserted a section of text below from the book I am
> writing on fluid preservation that summarizes the literature on
> isopropyl as a preservative.
>
> I would not use isopropyl at 50% as it can clear tissues at around 45%
> or less. If I had to use it, I would use a 70% solution mixed with
> deionized or distilled water.
>
> If I may ask, why are you buffering the alcohol, and to what pH? Most
> alcohol is slightly acidic (which makes a better preservative). I
> would be concerned, particularly with isopropyl, about making too
> basic a solution which could clear tissues. This could particularly
> be an issue with crayfish and mollusk shells, I would think, as they
> are going to further buffer the solution, aren't they? In any case,
> if you do have a good reason to buffer, I would use a more stable
> buffer than CaCO3.
>
> What is the glycerin for? Glycerin acts as a scavenger that will
> attract relative humidity and any contaminants in the air into your
> solution if your containers leak.
>
> Here is the text from the draft of the book, with citations:
>
> Isopropyl alcohol was first made in 1855, but it did not go into
> commercial production until 1920 in the United States (Hatch 1961).
> It was recommended as an alternative preservative to ethanol, without
> being tested, as early as 1922 (Griffin 1922). A notice in /Turtox
> News/ in 1934 complained of the high taxes on ethanol, the red-tape
> necessary to buy it tax-free, and the additives used to produce
> denatured ethanol. The recommended solution was isopropyl alcohol.
> The recommendation for its use came despite the fact that "Sufficient
> experimentation has not been carried on in connection with its use in
> biological work to warrant a dogmatic statement from us that it can
> /always/ be used as a substitute, but our preliminary work justifies
> this /belief/" (Windsor 1934:216). There was a conflict-of-interest
> in the recommendation to change to isopropyl alcohol: "Where can you
> buy isopropanol? Turtox will gladly accept your orders for it"
> (Windsor 1934:217). At that time, anhydrous isopropanol was $3.75 per
> gallon (for an 88% solution), but "the grade used for general
> preservation" was just $2.50/gallon (Windsor 1934:217).
>
>
> In 1922, Philip Pope preserved one specimen of a newt each in jars of
> 40%, 50%, 60%, 70% and 80% isopropanol, with one specimen in 70%
> ethanol for a control (Pope 1928). Pope examined the newts after a
> mere six years in the preservative, and decided that the 40-50%
> isopropyl preserved specimens were fine, even though he could not find
> the control to compare them to. The advantages that Pope listed for
> isopropyl were that it had no restrictions, was inexpensive, could be
> used in low concentrations, was not irritating like formaldehyde, and
> did not soften bones or teeth like formaldehyde (Pope 1928). However,
> 45-50% isopropanol has been shown to cause considerable shrinkage of
> specimens, it can be difficult to mix thoroughly, it is prone to
> layering in specimen containers, it may soften bone, and it may cause
> clearing of tissues if concentrations fall below 30-40% (Fink et al.
> 1979). DiStefano et al. (1994) found 50% isopropyl failed to prevent
> tissue decay in fish and crayfish. The permeability of the epidermis
> (the solute absorbed per ml of tissue) for methanol is 0.6, for
> ethanol 0.9, and for propanol 1.3, thus isopropyl penetrates epidermis
> best (Schaefer et al. 1982). It is important to note that isopropyl
> is twice as toxic as ethanol (Monick 1968).
>
>
> King and Porter (2004) reported observational data that long-term
> storage in isopropyl alcohol results in greater fading of ant
> specimens, probably due to the greater propensity of isopropyl and
> other long-chain alcohols to extract lipids, proteins, and pigments
> from cellular membranes at high concentrations (Goates and Knutson
> 1994). Some workers, particularly ichthyologists, have reported that
> they prefer isopropyl preserved specimens because they are more
> flexible than alcohol preserved specimens (Fink et al. 1979, Walker et
> al. 1995); however, isopropyl preserved specimens are flexible because
> the tissue matrix has undergone more breakdown that tissues do in
> ethanol (Stoddard 1989); in an accelerating aging study, Von Endt
> (2000) found that isopropyl induces more deterioration of collagen
> than ethanol.
>
>
> When isopropyl is mixed with water, the resulting solution undergoes
> contraction, so solutions should be mixed on a weight basis rather
> than a volume basis (Hatch 1961).
>
>
>
> All preserving alcohols cause tissue shrinkage, but the amount of
> shrinkage is variable, with less shrinkage occurring in methyl and
> more in isopropyl compared to ethyl alcohol (Ciferri 1971).
>
>
> Ciferri, A. 1971. Swelling and phase transition of insoluble
> collagen. Pages 101-151 _in_ Elden, H. R. (editor). /Biophysical
> Properties of the Skin/. John Wiley and Sons, Inc., New York, vii +
> 645 pages.
>
> DiStefano, R.J., M.J. Roell, B.A. Wagner, and J.J. Decoske. 1994.
> Relative performances of four preservatives on fish and crayfish.
> /Transactions of the American Fisheries Society/ 123:817-823
>
> Fink, W.L., K.E. Hartel, W.G. Saul, E.M. Koon, and E.O. Wiley. 1979.
> A report on current supplies and practices used in curation of
> ichthyological collections. American Society of Ichthyologists and
> Herpetologists ad hoc Subcommittee Report, 63 pages.
>
> Goates, C.Y. and K. Knutson. 1994. Enhanced permeation of polar
> compounds through human epidermis. I. Permeability and membrane
> structural changes in the presence of shorter chain alcohols.
> /Biochimica et Biophysica Acta/ 1195:169-179.
>
> Griffin, L.F. 1922. Practicable substitutes for grain alcohol.
> /Science/ 55(1419):262-263.
>
> Hatch, L.F. 1961. /Isopropyl Alcohol/. McGraw-Hill Book Company,
> Inc., New York, x + 184 pages.
>
> King, J.R., and S.D. Porter. 2004. Recommendations on the use of
> alcohols for preservation of ant specimens (Hymenoptera, Formicidae).
> /Insect Sociaux/ 51(2):197-202.
>
> Monick, J. A. 1968. /Alcohols: Their Chemistry, Properties and
> Manufacture/. Reinhold Book Corporation, New York, xiv + 594 pages.
>
> Pope, P.H. 1928. Isopropyl alcohol as a preservative. /Science/
> 68(1768):487-488.
>
> Schaefer, H., A. Zesch, and G. Stuttgen. 1982. /Skin Permeability/.
> Springer-Verlag, Berlin, ix + 541-896 pages.
>
> Stoddard, R. W. 1989. Fixatives and preservatives: their effects on
> tissue. Pages 1-25 _in_ Horie, C. V. (editor). /Conservation of
> Natural History Specimens: Spirit Collections/. The Manchester
> Museum and Department of Environmental Biology, The University of
> Manchester, Manchester, viii + 115 pages.
>
> Von Endt, D.W. 2000. Staying in shape: the stability of structural
> proteins in natural history museum storage fluids. /Polymer
> Preprints/ 41(2):1794-1795.
>
> Walker, H.J., G.H. Burgess, A.Y. Suzumoto, C.I. Klepadio, L.
> VanGuelpen, and J.M. Humphries. 1995. Isopropanol revisited.
> /Curation Newsletter/ 11:3-4.
>
> Windsor, A. S. 1934. Alcohol notes. /Turtox News/ 12(11):215-217.
>
>
> --John
>
> John E. Simmons
> Museologica
> 128 E. Burnside Street
> Bellefonte, Pennsylvania 16823-2010
> simmons.johne at gmail.com <mailto:simmons.johne at gmail.com>
> 303-681-5708
> www.museologica.com <http://www.museologica.com>
> and
> Adjunct Curator of Collections
> Earth and Mineral Science Museum & Art Gallery
> Penn State University
> 19 Deike Building
> University Park, Pennsylvania 16802-2709
> jes67 at psu.edu <mailto:jes67 at psu.edu>
>
>
> On Thu, Nov 5, 2009 at 4:35 PM, Alexandra M Snyder <amsnyder at unm.edu
> <mailto:amsnyder at unm.edu>> wrote:
>
> Any ideas and/or caveats re: use of isopropyl for invertebrate
> preservation? See letter below. Thank you in advance for
> information provided. Lex
>
> Lex,
>
> I just exhausted my last supply of ethanol, so I'll be
> fixing crayfishes and freshwater mollusks in iso and
> storing as well (theoretically). It is 99% ACS Iso and as
> far as I can ascertain using Google, not denatured. The
> plan for now is to try and buffer (CaCO3) and add a little
> glycerin as I do with denatured ethanol. My guess was
> diluting to 50% isopropyl.
>
> Ryan
> Ryan Evans, Aquatic Zoologist
> Kentucky State Nature Preserves Commission
> 801 Schenkel Lane, Frankfort, KY 40601
> 502-573-2886; ryan.evans at ky.gov <mailto:ryan.evans at ky.gov>
>
> The world is made for people who aren't cursed with self
> awareness. - Annie Savoy
>
> **************************************
> Alexandra M Snyder
> Collections Manager-Fishes
> Museum of Southwestern Biology MSC03-2020
> 302 Yale NE
> University of New Mexico
> Albuquerque NM 87131 USA
> PH/FAX 505.277.6005
> http://www.msb.unm.edu/fishes/index.html--
>
>
--
H.J. Walker, Jr.
Scripps Institution of Oceanography
University of California, San Diego 0208
La Jolla, CA 92093-0208
USA
hjwalker at ucsd.edu
phone:858-534-2199 fax:858-534-5306
Campus street address for FedEx, UPS, DHL:
8675 Discovery Way, 224 / 231 Vaughan Hall
La Jolla, CA 92037
SIO Marine Vertebrate Collection web site:
http://collections.ucsd.edu/mv/
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