I would add three additional pointers: 1) Assess in a darkened room with eyes acclimated to the dark; 2) Use a powerful light source--the apple green birefringence will be more obvious and easier to discriminate from the white of collegen; and 3) Assessment sensitivity is further increased if instead of using the inexpensive films that Tim describes you use a more traditional polarizing microscope or a regular light microscope with an polarized lens above the objectives (my microscope has a slide-in slot) and another above the field lens (I use a removable circular polarizer that fits over the entire field lens). Bruce
On Tue, Jul 28, 2020 at 3:06 PM Morken, Timothy via Histonet < histonet@lists.utsouthwestern.edu> wrote: > I neglected to mention sections should be cut at 10um for best results. > > Tim Morken > Supervisor, Electron Microscopy/Neuromuscular Special Studies > Department of Pathology > UC San Francisco Medical Center > > > -----Original Message----- > From: Morken, Timothy via Histonet <histonet@lists.utsouthwestern.edu> > Sent: Tuesday, July 28, 2020 11:57 AM > To: Ken M <kdea...@hotmail.com> > Cc: Histonet <histonet@lists.utsouthwestern.edu> > Subject: Re: [Histonet] Apple Green Birefringence in Amyliod slides > > Ken, Yes, polarized light and apple green birefringence is diagnostic for > amyloid with congo red and is the best practice. If you have a problem with > known control slides there are two possibilities: 1) make up fresh > solution. The pH has to be right. Or 2) try other control slides. Maybe you > cut through the amyloid area. > > Because we have hundreds of microscopes in our department most just use > polarized film as the polarizer (put over the light source) and another put > over the top of the slide as the analyzer. Turn one of the polarizing > slides and you will see the birefringence appear. > > Source: > "Polarizing film, 2"" x 2"" , PK/10 (BEST For use as a microscope > polarizer)" Cat# S07372 Thermo Fisher Sci Health $36.75 > PK/10 "2" x 2" > > These are polarized film mounted in 2" film holders (like the old > Kodachrome slides). > > Cheap and effective. (and avoids consternation from people losing > expensive microscope polarizers) > > Tim Morken > Supervisor, Electron Microscopy/Neuromuscular Special Studies Department > of Pathology UC San Francisco Medical Center > > > -----Original Message----- > From: Ken M via Histonet <histonet@lists.utsouthwestern.edu> > Sent: Tuesday, July 28, 2020 11:43 AM > To: histonet@lists.utsouthwestern.edu > Subject: [Histonet] Apple Green Birefringence in Amyliod slides > > Hi everyone. I was wondering if anyone out there has any experience with > diagnosing Amyloid tissue using Congo Red stained Kidney using polarized > lenses. Is it common to use polarized light to detect Amyloid deposits? > Does the absence of the "apple green birefringence" indicate a problem with > the control tissue or the control slides? Should this green bifringence > always appear to confirm the diagnosis? I know that the tissue should be > cut thicker than normal (we usually cut at 5), but in the future maybe we > will cut at 7 or 8? > _______________________________________________ > Histonet mailing list > Histonet@lists.utsouthwestern.edu > > https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.utsouthwestern.edu_mailman_listinfo_histonet&d=DwICAg&c=iORugZls2LlYyCAZRB3XLg&r=7cy9qXFa73jDX2Iixpjkq1XlWAfHgLLHm33agI_sCKA&m=2jEHe8Hf3ieiSbv1r-ZtSy-mm4FVj1XtTmUSGcfJmE8&s=Q_PpmT_KF2fDUvt9ltFVZLp6ctjM3xkK0RsfuUYW73c&e= > > _______________________________________________ > Histonet mailing list > Histonet@lists.utsouthwestern.edu > > https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.utsouthwestern.edu_mailman_listinfo_histonet&d=DwICAg&c=iORugZls2LlYyCAZRB3XLg&r=7cy9qXFa73jDX2Iixpjkq1XlWAfHgLLHm33agI_sCKA&m=oqbw0CqyFQtZ-sA1KdA3LJ03sCqCrnmvdp3OwwX6wNM&s=60acNUmFhia7wnxpRNPpNBpiz35pC5Rd-Xullc7MbNk&e= > > _______________________________________________ > 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