<div dir="ltr"><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:#000000">
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif">This is really a management issue,
the key consideration being the resource investment in the process vs the usefulness of the specimen that results from the process. Of course you can make fluid-preserved specimens from frozen animals, but is it worth the
time and chemicals it will take to do it? Does the specimen quality justify the time and chemicals required?<span></span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span> </span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif">What I said in <i>Herpetological
Collecting and Collections Management</i> (3<sup>rd</sup> edition, 2015) is
that “Once a specimen has been frozen, it is <u>usually</u> not possible to make a
satisfactory fluid preserved preparation from it” due to the rupture of cells
from freezing and thawing (thawing usually causes more damage to tissues than does
freezing) which weakens the structural integrity of the tissues, thus “Frozen
specimens are <u>best prepared</u> as skeletons” (emphasis added in both quotations).<span></span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span> </span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif">I also recommended that if you do
need to make a fluid-preserved prep from a frozen specimen that it should be
thawed in a buffered formaldehyde solution and injected progressively as
thawing permits—this step is important because, as Andy stated, fixatives and preservatives
cannot penetrate frozen tissues. If you fail to inject specimens as they thaw the outermost tissues become fixed long before the inner tissues,
resulting in an unevenly fixed specimen. For large specimens, you should mark
injection sites on a sketch of the specimen or put pins in the needle punctures
to ensure that the specimen is injected evenly as it thaws.<span></span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span> </span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif">Andy’s recommendation to stage the
specimen from formaldehyde up to the desired ethanol concentration should also
be followed, as this has been demonstrated to reduce shrinkage, it leaves much
less formaldehyde in the specimen (the trace amounts of formaldehyde will
eventually show up in the alcohol the specimen is in), and overall makes a
better specimen.<span></span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span> </span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif">There are several studies that
have looked at the problems of fluid preservation of frozen specimens, which I
summarized in <i>Fluid Preservation: A Comprehensive Reference</i> (2014), and
I also reported on shrinkage and color changes due to freezing. To briefly summarize,
freezing disrupts the arrangement of myofibers, distorts sarcolemmas (connective
tissue sheaths), the time lag between death and when the animal is thoroughly
frozen allows for extensive autolysis and biological deterioration to take
place, and there is a lot of tissue damage and cell rupture from the formation of ice crystals during both freezing and thawing cycles.<span></span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span> </span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif">If you want to take tissues from a
frozen specimen, that should be done before the specimen is preserved, preferably while
it is still frozen as thawing initiates the degradation of DNA, but be warned that tissue from such specimens will be degraded compared to tissues removed and processed immediately after the specimen was euthanized. Be sure to
label all tissues removed from frozen specimens as likely to be degraded. Also, add a note
in the catalog record if a fluid-preserved specimen was made from a frozen
specimen—this information will be of use for future research use of the
specimen.<span></span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span> </span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif">Lastly, about skeletons—given the
choice between preparing a good skeleton or a fair fluid-preserved
preparation, why not opt for the good skeleton? Most herpetological collections are
woefully deficient in good skeletal material. If the specimen is needed as an
identification voucher, you can take digital photographs of the specimen, link them to the
specimen record in the database for confirmation of ID, and still prepare a
very useful skeleton from the specimen.</p><p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><br></p><p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif">--John</p><p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><br><span></span></p>
</div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><font size="2"><span style="font-family:tahoma,sans-serif">John E. Simmons<br>Writer and Museum Consultant</span></font></div><div dir="ltr"><font size="2"><span style="font-family:tahoma,sans-serif">Museologica<br><i>and</i><br>Associate Curator of Collections<br>Earth and Mineral Science Museum & Art Gallery<br>Penn State University<br><i>and</i><br>Investigador Asociado, Departamento de Ornitologia<br>Museo de Historia Natural, Universidad Nacional Mayor de San Marcos, Lima</span></font><br></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Apr 27, 2022 at 9:24 AM Bentley, Andrew Charles <<a href="mailto:abentley@ku.edu">abentley@ku.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div lang="EN-US">
<div class="gmail-m_7291451870965256873WordSection1">
<p class="MsoNormal">Hi Tonya<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">It is true that frozen specimens do not make ideal ethanol specimens as the formalin and ethanol do not pervade the tissues as well when frozen an thawed. You can counteract some of that by injecting with formalin into all body cavities
and leaving it soaking in formalin for a little longer. It also helps to step the specimen up through concentrations of ethanol to ensure good preservation throughout the specimen.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Andy<u></u><u></u></p>
<div>
<p class="MsoNormal"><span lang="EN-AU"> A : A : A :<br>
}<(((_°>.,.,.,.}<(((_°>.,.,.,.}<)))_°><br>
V V V<br>
Andy Bentley<br>
Ichthyology Collection Manager<br>
University of Kansas<br>
Biodiversity Institute<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU">Dyche Hall<br>
<a>1345 Jayhawk Boulevard</a><br>
<a>Lawrence, KS, 66045-7561</a><br>
<a>USA</a><br>
<br>
Tel: <a href="tel:%28785%29%20864-3863" target="_blank">(785) 864-3863</a><br>
Fax: <a href="tel:%28785%29%20864-5335" target="_blank">(785) 864-5335</a> <br>
Email: <a href="mailto:abentley@ku.edu" target="_blank">abentley@ku.edu</a> <u></u><u></u></span></p>
<p class="MsoNormal">ORCID: <span style="color:rgb(73,74,76);background:white none repeat scroll 0% 0%"><a href="https://orcid.org/0000-0002-3093-1258" target="_blank">https://orcid.org/0000-0002-3093-1258</a><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU"><a href="http://ichthyology.biodiversity.ku.edu/" target="_blank">http://ichthyology.biodiversity.ku.edu</a></span><u></u><u></u></p>
<p class="MsoNormal"> A : A : A :<br>
}<(((_°>.,.,.,.}<(((_°>.,.,.,.}<)))_°><br>
V V V<u></u><u></u></p>
</div>
<p class="MsoNormal"><u></u> <u></u></p>
<div>
<div style="border-color:rgb(225,225,225) currentcolor currentcolor;border-style:solid none none;border-width:1pt medium medium;padding:3pt 0in 0in">
<p class="MsoNormal"><b>From:</b> Nhcoll-l <<a href="mailto:nhcoll-l-bounces@mailman.yale.edu" target="_blank">nhcoll-l-bounces@mailman.yale.edu</a>> <b>
On Behalf Of </b>Haff, Tonya (NCMI, Crace)<br>
<b>Sent:</b> Tuesday, April 26, 2022 11:26 PM<br>
<b>To:</b> <a href="mailto:nhcoll-l@mailman.yale.edu" target="_blank">nhcoll-l@mailman.yale.edu</a><br>
<b>Subject:</b> [Nhcoll-l] prepping frozen herps<u></u><u></u></p>
</div>
</div>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><span lang="EN-AU">Hello all,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU">I have read (in John Simmon’s book on herpetological collecting, among other places) that frozen snake and lizard specimens do not make suitable formalin-preserved specimens, and should be instead skeletonised. We have
quite a few herp specimens in the freezer that we have been planning on prepping as ‘pickles’ (fixed in formalin and then stored in ETOH), but I haven’t started yet because of the concern that it may not be worthwhile. I wonder if any of you could weigh in
on this and tell me what your experiences have been, and whether or not you would bother preserving these specimens in spirit, or if we should just prep them as skeletons?<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU">Thanks!<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU">Tonya<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU">-------------------------------------------------<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU">Dr. Tonya M. Haff<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU">Collection Manager<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU">Australian National Wildlife Collection<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU">CSIRO<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-AU"><u></u> <u></u></span></p>
</div>
</div>
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