>>> On 20/03/2008 at 4:27 a.m., Stanislas DUBOIS <Stanislas.Dubois from ifremer.fr>
> For safety and health reasons, formaldehyde (formol) will be soon
> prohibited (at least in Europe .. I'm not sure for other countries).
> That might be problematic for specimen preservation since, as many of
> you I guess, I used to fix collected polychaetes from benthic samples in
> formaldehyde. I just learned that RCL2 might be of great interest to
> substitute for formol. Does anyone already experience this surrogate
> formol or does anyone has any information to share with me, as far as
> fixation quality of tissues for IDs (I'm not talking of doing any
> molecular analysis), preservation of pigments etc....
Thanks for the news Stan. My guess is that RCL2 has yet to spread far in the medical world, and even less into general use.
The formulation is not public but contains acetic acid (vinegar). Perhaps someone can find out how much more expensive it is compared to formalin, bearing in mind that it's the medical/pathology market that they're selling it into.
Those interested can check the company web page:
http://www.alphelys.com/site/us/pFF_FixateurSansFormol.htm
The paper of 2006 by Delfour et al that they cite, is available full text at pubmed
"RCL2, a New Fixative, Preserves Morphology and Nucleic Acid Integrity in Paraffin-Embedded Breast Carcinoma and Microdissected Breast Tumor Cells"
http://www.pubmedcentral.nih.gov/
just search for rcl2.
Yes, there is a general understandable reluctance of field workers to use formalin these days. I dislike working with it also. But, I find the usual substitute - ethanol - can result in rigid brittle specimens that are very inferior to those formalin-fixed for morphology and identification, or in disintegrating rubbish in bulk, sediment-laden samples.
Geoff
--
Geoff Read <g.read from niwa.co.nz>
http://www.annelida.net/http://www.niwascience.co.nz/ncabb/
