Red oil of Thyme is frequently imported and sold under the name of oil of
Origanum; it is often adulterated with oils of turpentine, spike lavender
and rosemary, and colored with alkanet root. It also contains thymol and is
not recommended.

True oil of Origanum is extracted from Wild Marjoram (Origanum vulgare), and
other species of Origanum. The best oil comes from Crete, is very volatile
and costs as much as $50.00 US per 25 ml. According to Langhans (Ehrlich's
'Encyklopadie') permanent mounts were made using oil of Origanum to clear
and mount after dehydrating through alcohols. This iodine method and others
have been proven to be non-specific and not very permanent. If you must use
this technique,
try oil of bay or bergamot, they have similar refractive indexes and should
work as well.

Other techniques like: McManus PAS, Best's carmine or an Alcian blue can
also be of value for the demonstration of carbohydrates without the smoke
and mirrors.



Eric C. Kellar
University of Pittsburgh Medical Center



	----------
	From:  lmiller@wlgore.com [SMTP:lmiller@wlgore.com]
	Sent:  Tuesday, December 14, 1999 11:54 AM
	To:  histonet@pathology.swmed.edu
	Subject:  Oil of Origanum



	Hi all!
	I've been asked to do an iodine stain for carbohydrates, and the one
listed in
	Sheehan's calls for mounting in oil of origanum. Is there something
that I can
	use instead?

	Thanks in advance,
	Lori Miller