[Nhcoll-l] Telling formalin from ethanol

[A.J.van_Dam at lumc.nl]

Dear Megan,

A simple and safe method to distinguish ethanol and formalin filled specimens jars:

If you throw a tiny torn piece of paper in the jar, in ethanol it will sink right away.
Thrown in a jar with formalin (or any other water-based preservative) it will keep flowing for a very long time and it will be even hard to get it sunk to the bottom of the jar.
Only by putting the paper first in ethanol, you can make it easily sink which is quite handy when wanting to add labels in formalin and/or glycerine.

Using tweezers to put/hold the paper in the fluid of the jar and watch its action (sinking or flowing) will keep you in control over the procedure without having to fish for sunken pieces of paper.

Kind regards,

Dries
Andries J. van Dam, conservator

Museum of Anatomy
Leiden University Medical Center
Building 3 (V3-32)
P.O.Box 9600
2300 RC Leiden
The Netherlands
tel: +31 (0)71 52 68356
E-mail: A.J.van_Dam at lumc.nl<mailto:A.J.van_Dam at lumc.nl>
Visiting address: Hippocratespad 21
Scientific associate Natural History Museum London
http://www.nhm.ac.uk<http://www.nhm.ac.uk/>
Directory Board member ICOM-CC
http://www.icom-cc.org<http://www.icom-cc.org/>

Director Alcomon Company
http://www.alcomon.com<http://www.alcomon.com/>


From: nhcoll-l-bounces at mailman.yale.edu [mailto:nhcoll-l-bounces at mailman.yale.edu] On Behalf Of Best, Megan
Sent: donderdag 6 maart 2014 15:03
To: nhcoll-l at mailman.yale.edu
Subject: [Nhcoll-l] Telling formalin from ethanol


Hello all,

I've been benefitting from the conversations on this listserv for some time now, really fascinating and useful stuff.  I manage a research collection, mostly of marine invertebrates, and I have a question:

Is there an easy way to tell if a fixative is formalin or ethanol?  Aside from the smell test!  I'm looking to organise hundreds of jars from various benthic surveys, and we want to switch out anything that's in formalin to ethanol.  The formalin is buffered so I don't think a pH difference would be a strong indicator.  Any ideas/advice would be appreciated.

-Megan

Megan Best
Invertebrate Taxonomy
tel: 902.426.2791   email: megan.best at dfo-mpo.gc.ca<mailto:megan.best at dfo-mpo.gc.ca>
Ocean and Ecosystem Sciences Division | Division des sciences de l'écosystème et de la mer
Department of Fisheries and Oceans | Ministère des Pêches et Oceans
Government of Canada | Government du Canada
Bedford Institute of Oceanography | Institut Océanographique de Bedford
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