RE: Re Oil red staining

From:"Morken, Tim" <>

Well, for whatever reason osmium will preserve large fat droplets in tissue
and I have used it to demonstrate lipid storage diseases in paraffin
sections. So, I can't give you the chemistry, just the observed results.


-----Original Message-----
From: Philip Oshel []
Sent: Thursday, May 17, 2001 11:21 AM
To: Morken, Tim
Subject: RE: Re Oil red staining

A question: is this really the case? Osmium binds across double-bonds 
of lipids, which is why it shows and preserves membranes, but it 
binds poorly or not all at to saturated lipids. So I wouldn't expect 
OsO4 to show fatty deposits if the fats are saturated. Oil Red O and 
Sudan Black, which more mix into the lipids and don't react with 
them, would show fat deposits that OsO4 doesn't, and are better fat 


>Agreed, there would be no need to do special fat stains if the tissue is
>processed with osmium. In fact, this can be done for paraffin embedding as
>well to show fat distribtion in some diseases with vastly better morphology
>and localization than frozen sections.
>Tim Morken
>CDC, Atlanta
>-----Original Message-----
>From: Saby, Joseph []
>Sent: Thursday, May 17, 2001 6:15 AM
>To: '';
>Subject: RE: Re Oil red staining
>Whenever I've worked with those plastics, there has always been a clearing
>stage through acetone.  Since acetone would remove all non-bound fat, Oil
>Red O would have nothing to go into.
>When I've worked with these plastics, I also did a post-fixation in osmium
>tetroxide, which does a very good job of staining fats and lipid (it turns
>them black).  Perhaps this would work for your purposes.
>Joseph A. Saby, BA, HT(ASCP)
>Drug Safety Evaluation
>Pfizer Global Research and Development
>2800 Plymouth Road
>Ann Arbor, MI 48105
>Phone: (734)-622-3631
>FAX:   (734)-622-3866
>-----Original Message-----
>From: []
>Sent: Thursday, May 17, 2001 2:49 AM
>Subject: Re Oil red staining
>Jaclynn Lett
>Has anyone used Oil Red O to stain lipids in tissues embedded in plastics
>(Epon or Epon-Araldite)?  If so, has this been done by staining en bloc or
>by staining the sections.  Sections would range from 1-4 microns in
>A couple of people so far have commented on how hard this would be, and our
>experience agrees with theirs.
>HOWEVER Jaclynn also said:
>We would also consider tissues embedded in glycol methacrylate.  We'd like
>to avoid frozen sections because we'd prefer the higher level of detail
>possible with plastic.
>In THAT case things look better! Would you settle for Sudan black, rather
>than Oil red staining of the lipid? If 'yes' then there is a method - which
>does indeed show even tiny droplets of lipid very clearly. This was worked
>out by the one-time king of GMA staining Peter Gerrits, and can be found in
>Neurosci Methods, as follows:
>      Gerrits PO, Brekelmans-Bartels M, Mast L, 's-GrAavenmade EJ, Horobin
>and Holstege G. (1992)..
>      Staining myelin and myelin-like degradation products in the spinal
>cords of chronic experimental
>      allergic encephalomyelitis (Cr-EAE) rats using Sudan Black B staining
>of glycol methacrylate-embedded
>      material.
>      J. Neuroscience Methods. 45, 99-105
>Bye - Richard Horobin
>Institute of Biomedical & Life Sciences, University of Glasgow
>T direct 01796-474 480 --- E
>"What should we expect? Everything."

Philip Oshel
Supervisor, AMFSC and BBPIC microscopy facilities
Department of Animal Sciences
University of Wisconsin
1675 Observatory Drive
Madison,  WI  53706 - 1284
voice: (608) 263-4162
fax: (608) 262-5157 (dept. fax)

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