Hi Julio, I can speak to a research / core setting where I often advised my users to place their tissues in 70% ethanol following adequate formalin fixation to maintain epitopes for potential downstream IHC studies. I have found tissue can be placed in 70% and maintained indefinitely. They do not 'unfix'.
Recently though I was speaking to a pathologist who doesn't like that protocol as she sees nuclear changes in tissues that have been in 70% for extended periods. So, yes, I think that idea is good in principle. I would say that the staff time taken, and extra reagent costs, of changing all those biopsies over into another solution, plus the additional chemical waste generated is not worth simply making sure the original formalin containers are well sealed after grossing and / or purchasing one of those specimen collection cupboards that filters the air coming through. I do understand the dangers of formalin, but considering how much of it is in use and how many of us on this list have been exposed to it for the majority of our lives and we are still OK! (well, maybe, I suppose that depends on your definition of OK is :) Leica seem to think this is OK too! http://www.leicabiosystems.com/pathologyleaders/fixation-and-fixatives-5-practical-procedures-to-optimise-quality-the-effects-of-heat-and-microwaves/ Ultimately you would have to perform studies to check the effects on your downstream processes and proof this procedure in your own lab. yours, mills On Sun, Oct 16, 2016 at 10:57 AM, Julio Benavides via Histonet < email@example.com> wrote: > > Hi there, > > This is me again with formalin issues. The health and safety officer of my > institute keeps on in her crusade of eliminating formalin from the world. > After your helpful emails, I convinced her that you do need formalin to fix > samples, other approach would need to much setup IHC protocols. Then and > with good intention at heart, she has suggested that, one possible solution > to reduce formalin presence in the institute could be, once samples have > been fixed in buffered formalin (10%) and embedded in wax, to substitute it > by 70% ethanol until the sample is discharged. Has anybody tried anything > similar? What do you think? Would it be possible to come back to formalin > in case of necessity (let´s say we want to retrim fixed samples after they > have been in ethanol 70% for 5 months… would you trust them for IHC? HE?). > > Thanks again for your help > > Julio > > > > _______________________________________________ > Histonet mailing list > Histonet@lists.utsouthwestern.edu > http://lists.utsouthwestern.edu/mailman/listinfo/histonet > -- Caroline Miller (mills) Director of Histology 3Scan.com 415 2187297 _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet