[Histonet] Mold Release Problems

[joelle weaver]

I have never seen a published reference unfortunately that I can direct you to. I do not use mold release because I have never had any trouble with this while embedding. It seems to me that if standard metal base molds are used, and they are kept clean, the blocks come out easily if they are fully hardened.  However I know with those so-called "turbo" molds, release can be more difficult, and also with those plastic disposable ones ( which I also don't like, and my reason with the plastic ones is that the ones I have encountered is that they do not have a completely flat surface at the block face and so when the block is finished it is concave). But I know some people really like the mold release product and each of the different types of molds, so to each his own. So even though I don't use mold release, I suspect however,  that it is some kind of silicone or other chemical that creates a residue that coats the surface of the base mold so that the paraffin is not in direct contact with the mold. It would have to be  mostly non-miscible with paraffin to be able to form a barrier between the two. And,  if it has any kind of solvent like materials (check out the label or MSDS if it is not a trade secret)- Or someone in histoland may know the constituents off hand? But  my suspicion is that the materials are not miscible with the paraffin, and also not with anything aqueous. If you used this in excess, common sense would say that residue could cause any number of problems in the subsequent steps of microtomy and staining. 




Joelle Weaver MAOM, HTL (ASCP) QIHC
 > Date: Fri, 9 Nov 2012 15:16:56 -0800
> From: bluebird8081 <@t> yahoo.com
> To: histonet <@t> lists.utsouthwestern.edu
> Subject: [Histonet] Mold Release Problems
> 
> Does anyone know of a reference for the problems from using mold release?  When too much is used on the mold it eats into the block and causes the ribbons to explode on the water bath and creates an artifact in the tissue.I cannot find a reference for it or any published material about the problem but have been to seminars where it was discussed.When it is not used the problem never occurs.
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