We often get large volumes of blocks from other countries that must be reembedded.  I melt them in a tray in our paraffin oven at 60C but some others in the lab feel that it should be done at a higher temperature to speed up the process.

	-----Original Message----- 
	From: John Kiernan [mailto:jkiernan@uwo.ca] 
	Sent: Mon 2/21/2005 11:15 AM 
	To: Bartlett, Jeanine 
	Cc: Histonet 
	Subject: Re: [Histonet] re-embedding blocks
	
	

	I don't know about "generally". When I do this
	(which isn't often) I use the same temperature as
	for infiltration, which in my lab is about 60C for
	a 58C wax. It works. Why do otherwise?
	
	With regard to "a temperature that is generally
	considered too high either for the paraffin or
	for the tissue", you can expect a variety of
	replies because this is controversial. A popular
	notion is that too-hot makes the tissue unduly
	hard to cut. I don't agree, but that's another
	story, and there's plenty of HISTOMYTHOLOGY in
	this area.
	
	John Kiernan
	Dept of anatomy & Cell Biology
	University of Western Ontario
	London, Canada.
	_______________________________________________
	
	Bartlett, Jeanine" wrote:
	>
	> Hi everybody:
	>
	> Just curious as to what oven temperature is generally used for melting
	> down paraffin blocks for re-embedding.  Is there a temperature that is
	> generally considered too high either for the paraffin or for the tissue?
	>
	> Thanks!
	> Jeanine Bartlett, HT(ASCP)
	> Centers for Disease Control and Prevention
	> Infectious Disease Pathology Activity
	> 1600 Clifton Road, MS/G-32
	> Atlanta, GA 30333
	_______________________________________