[Histonet] Osmium tetroxide staining for lipids

[Morken, Timothy]

Sheila, You can't normally use osmium lipid fixation for paraffin sections because the lipid you want to see will usually have been dissolved out by the paraffin processing. You need to either post-fix in osmium (after formalin) before paraffin processing or use frozen sections. As mentioned, once fixed in osmium other histology stains don't work so well because the tissue is rendered black and the osmium interferes with many stains.

Barry Rittman gave the procedure for frozen sections. You MUST use it in an exterior-vented chemical fume hood (NOT one with filtered air blowing out the top as in a biosafety cabinet or bench top unit).

Using osmium is not worth the trouble for one-off or even occasional cases. It is time consuming to prepare, must be stored in the dark in well-sealed triple containers each sealed with parafilm wrap or the vapor will escape and blacken everything in the refridgerator or cupboard. It is not something to take lightly. If you can smell it, it is fixing your nose! Disposal is a hassle as well.

If you have access to an EM lab then they can do it for you and save you the hassle.

Otherwise use the other methods mentioned.


Tim Morken
Supervisor, Electron Microscopy/Neuromuscular Special Studies
Department of Pathology
UC San Francisco Medical Center
505 Parnassus Ave, Box 1656
Room S570
San Francisco, CA 94143

(415) 353-1266 (ph)
(415) 514-3403 (fax)
tim.morken <@t> ucsfmedctr.org





-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu [mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Sheila Adey
Sent: Friday, August 24, 2012 5:30 AM
To: histonet <@t> lists.utsouthwestern.edu
Subject: [Histonet] Osmium tetroxide staining for lipids


Hi Everyone:
 
One of my pathologists wants me to look into Osmium Tetroxide for staining lipids. From what I can gather on the internet, it looks like it is used in Electron microscopy for fixation and staining.
Is anyone using this procedure for routine 4 micrometer sections?
 
Thanks
:)
Sheila 		 	   		  _______________________________________________
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