Dorothy, I personally order from Sigma and I have to tell you that in all my years of working with methyl methacrylate, they have been the most reliable source. I must admit that I did once use Fisher for a brief period of time due to pricing concerns from the purchasing department as there was something of an issue with the hazardous shipping from Sigma being almost as much as the MMA price, but not the case with Fisher. Honestly though I only used Fisher for about a year to a year and a half and switched back because of an issue with a particular lot that I encountered. During that particular issue my MMA blocks had polymerized with a sort of amber tint and with a pleasant orange fruity smell. It was alarming to me because I was completely used to having made crystal clear resin blocks and now I was starting to really love this orange smell during block preparation at the grinder that used to be a pungent MMA smell thats not really good for you under prolonged or excessive exposure. As time went by I then started to notice a change in polymerization rates and even sometimes an incomplete polymerization with a rubbery surface. While I did not recall any serious issue with staining, I did notice that cutting thin sections became a bit inconsistent and troublesome at times. It was then that I needed to discover if it was something that I was now doing differently than in the several years past of consistency or the chemicals that I was using. I ordered a new bottle off MMA from Sigma, changing only one variable, and ran a test. Turned out that I was back instantly to the clear blocks that I was accustomed to creating and that the issue had to be the Fisher bottle/lot of MMA. I want to point out that I am NOT saying that the Fisher MMA is an unreliable source of MMA. It was in my opinion clearly an issue of a bad lot/batch of product. However, given my OCD tendencies within the laboratory, I quickly reminded myself that "if it's not broke, don't fix it!" Basically, I shouldn't let pricing sacrifice the quality and consistency that I was accustomed to experiencing as I only switched suppliers due to a request for a cheaper alternative by the purchasing department. Oh and one more thing, I found out later that the orange smell was due to the presence of either solution or residue from the orange cleaning solution that the glass bottles are subjected to prior to filling with chemicals so like I said, could have been a one in a million experience but my mind told me I could not take any more chances! :) Best Regards, Jack
> From: dml...@gmail.com > Date: Fri, 31 Jan 2014 12:56:55 -0500 > To: abt...@gmail.com > Subject: Re: [Histonet] Where do you order MMA for undecalcified plastic > sectioning mouse bone? > CC: histonet@lists.utsouthwestern.edu > > Hi Dorothy, > > I buy Methyl Methacrylate from Fisher Scientific. > > -Damien L. > > Sent from my iPhone > > > On Jan 31, 2014, at 12:42 PM, Dorothy Hu <abt...@gmail.com> wrote: > > > > which company do you ordered MMA? > > Sigma has back order, so I try to find reliable resource here. > > > > Thanks, > > > > Dorothy > > abt...@gmail.com > > _______________________________________________ > > Histonet mailing list > > Histonet@lists.utsouthwestern.edu > > http://lists.utsouthwestern.edu/mailman/listinfo/histonet > > _______________________________________________ > Histonet mailing list > Histonet@lists.utsouthwestern.edu > http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
