Re: whole organ fixation with color retention

From:Robert Wadley

        Dear Louri,

        While the alcohol method does work, if left too long it will cause non-reversible fading.

        Fading of whole mounts is caused by oxidation during the fixation process - this is reversible.  Usually the addition of Sodium dithionite to the mounting solution does the trick.  Long term storage will also lead to fading as the pH of the mounting solution changes (usually becoming acidic over time).  Frequent monitoring (every 2 - 5 years) & replacement of the mounting media keeps everything looking colourful for decades.

        I probably have some more info at home somewhere, but its been 10 years since I was curator of a pathology museum, & my plans for a detailed manual have become just another pile of paperwork!!!

        Hope this helps


        Rob W.


At 02:39 PM 3/04/2002 +1000, Tony Henwood wrote:

My suggestion is to slice the organs, fix in buffered
formalin or Wentworth's fixative (see most
histotechnology textbooks for the formula) for 4 weeks
or more. Mount specimen in a perspex museum box. Rinse
specimen in 95% ethanol and leave in ethanol untill
colour comes back (brown bloody areas appear red),
replace ethanol with light paraffin oil, seal the box,
label and all done.


 --- Louri Caldwell <> wrote: > Hi
> We have a researcher interested in retaining whole
> organs for teaching
> purposes, but would like the original color of the
> organ to remain intact. 
> I know a similar topic was addressed not too long
> ago, and I have read the
> archives, but wanted to see if anyone had
> suggestions other than
> plastination.   Ideally, he would like a fixative -
> and the only one I've
> found a reference for contains chloral hydrate -
> which he can't purchase as
> a DEA number is required to do so.
> Any suggestions you may have would be greatly
> appreciated.
> Thank you,
> Louri

Robert Wadley
Senior Laboratory Manager
Flow Cytometry
Faculty of Veterinary Science
University of Sydney

Ph +61 2 9351 5827
Fax +61 2 9351 3957

RMC Gunn Building, B19, Room 212
Faculty of Veterinary Science
University of Sydney
Sydney, New South Wales, Australia, 2006

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