A stain I have never had a problem with. However I did have the good fortune to listen to Culling many years ago on the use of 1% periodic acid for PAS staining and he insisted periodic acid, no matter what the concentration, should be made fresh every time you do these stains e.g. PAS and PAMS. Some people use 0.5% but we used 1% for 15 minutes, and then did microwave staining for the methenamine silver. A 56C - 60C water bath also works plus monitoring the color of the sections - the color of dark tea.
This is NOT a stable oxidizer once made up, and never should be reused under any circumstances. On the chance you have not used this solution in over 1 1/2 years, you may not be getting proper oxidation of the basement membranes since the periodic acid and the methanamine silver may be bad. Also, the Methenamine silver should be no more than 6 months old. We also kept our silver nitrate solution fresh when we made up the methenamine silver solution, and do store our silver nitrate salts in the refrigerator since this is hygroscopic. Check on storage of this salt in MSDS I have never been one to use kits for either of these stains, particularly with periodic acid as a ready to use solution. This goes into solution very rapidly and be sure to oxidize for 10 minutes before going to the methenamine silver. None of these solutions is difficult to make up in house. If you want, I can send my method and also a protocol pdf from HistoLogic by Stanley Shapiro, where he used freshly made 0.5% periodic acid via private email. The nuclei will pick up some silver, but one should be able to discern nuclei from basement membranes on 1 to 2 µm sections. Good luck Gayle Callis HTL/HT/MT(ASCP) Bozeman MT You wrote: Just wanted to give a quick update on this. I had a suggestion for using thiosemicarbazide for 10 minutes after the periodic acid, and of all the things we tried, this was the only thing that worked. It eliminated the nuclear staining and the capillaries are now picking up the silver (as they should be!). Unfortunately, I accidently deleted the email that suggested this so I don't know who to thank, but it was a great suggestion! Liz From: Elizabeth Cameron Sent: Thursday, February 16, 2012 2:17 PM To: histonet <@t> lists.utsouthwestern.edu Subject: Jones/PAMS Hi, I was wondering if anyone has any suggestions for a Jones/PAMS stain that is not working properly. This is something we don't do often. The last time we did it was a year and a half ago, and it seemed fine at the time. We have tried 3 or 4 protocols, including an ammoniacal silver, and it is still not working properly. In some protocols, our red cells are staining but the capillaries in the glomeruli do not seem to be picking up the silver. In other protocols, there are nuclei of some cells that should not be staining that are, but again, the capillaries are not. We are working on mouse tissue that is fixed in NBF. The strange thing is the stain seems to be working well on Bouins and Telly's fixed tissue. I even tried mordanting in Bouins! We have tried multiple kidneys with the same results. We are on new bottles of silver and periodic acid, although our methenamine has been around a while. Any suggestions would be greatly appreciated. Thanks! Liz _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet