Hello Rene, thank you very much for the paper you sent me! I will read it tomorrow. > 20% NaOH is too strong. Actually, floating 4um nail sections on 20% NaOH does work. Very well. We just validated it today and the attending/staff derm path people are very happy with the results. We will continue to "float" difficult nails until we implement and validate a pre-soak protocol in the grossing lab. The key to making foatation work well is to re-float the sections on a regular water bath for several minutes to rinse out the NaOH. Residual NaOH will prevent adhesion to even the stickiest slides. My guess is the keratin network is crosslinked in many ways, and the NaOH treatment is degrading only some of them. What I have observed with 4um sections is they flatten out and "spread" while floating on NaOH -- very similar to how nail clippings swell up when soaked in 20% NaOH. Of course this can go too far and leave you with mush, but 4um sections can certainly withstand 20% NaOH (warm ~40C, not RT) for at least 15min. The derm pathologist said the morphology looked good. There's always more than one way... :) Thanks again for the paper! -brice
________________________________ From: Rene J Buesa [mailto:rjbu...@yahoo.com] Sent: Wednesday, January 27, 2010 3:49 PM To: Joe The Toe Nocito; Due, Brice Cc: histonet@lists.utsouthwestern.edu Subject: Re: [Histonet] 20% NaOH Nail pre-Treatment... Questions 20% NaOH is too strong. Under separate cover I am sending another procedure. René J. --- On Tue, 1/26/10, Due, Brice <b...@partners.org> wrote: From: Due, Brice <b...@partners.org> Subject: [Histonet] 20% NaOH Nail pre-Treatment... Questions To: "Joe "The Toe" Nocito" <jnoc...@satx.rr.com> Cc: histonet@lists.utsouthwestern.edu Date: Tuesday, January 26, 2010, 6:05 PM Hello Joe, first thanks so much for sharing your expertise here on Histonet. I work in the main histo lab at Mass General Hosp. in Boston and I have interested the powers that be in your NaOH protocol. I initially used your NaOH idea to attach an "impossible" nail to slides by floating 4um section on 20% NaOH for 10-15min. (The transfers between regular water bath and NaOH bath (and back to rinse) were surprisingly easy because the concentrated NaOH prevents adhesion to even the stickiest adhesive slides.) Anyhow, I have some questions for you about your lab's implementation. I found your most complete post at http://lists.utsouthwestern.edu/pipermail/histonet/2008-October/040078.html But I am concerned about the safety of 20% NaOH in routine use. Would you mind posting or emailing me any SOPs you have that address the safety issues? Specifically both the histology lab and the "grossing" labs here use RDO decal solutions at every bench. So there is/will be concern about the proper handling of 20% NaOH around RDO... by overworked PAs and residents, etc. etc. Feel free to tell me your safety almost-horror stories so we can (try to) prevent them from occuring here. I've seen that some people use 10% NaOH instead. Have you experimented with this? Any reasons you stick with 20% beyond the usual "it ain't broke, so..."? Have you (or anyone on Histonet) ever tried to find the minimum effective concentration? Increasing the pre-soak time isn't an issue here since I've been assured that nail turnaround times are non-critical. Along these lines, do you or anyone have any histochemical references for the reactions that are taking place? With this info it might be possible to predict the minimum effective pH. It would also be nice to have references for the SOP. (I know about the coverslip "crushes" some derm clinicians do with fresh scrapings. Alternately, do you know of any histochemical references for this?) Thank you so much for sharing your time and info! And if I happen to answer any of my own questions I will be sure to post what I learn. Sincerely, -brice Massachusetts General Hospital Surgical Pathology, Histology The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail. _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu <http://us.mc657.mail.yahoo.com/mc/compose?to=histo...@lists.utsouthwestern.edu> http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
