Hello All, I have successfully stained porcine and mouse paraffin embedded heart tissues with Movat’s Pentachrome (MP), using EMS’ MP solutions and protocol (http://www.emsdiasum.com/microscopy/technical/datasheet/26385.aspx), with some optimization on times.
However, now I am working with archival human tissue that has been fixed for much longer and is much older than my other samples (Human Aorta & Aortic Valve, formalin fixed 2-6 months or 2-4 years, embedded in paraffin and stored at RT for ~6 years). I cannot seem to get the Woodstain Scarlet-Acid Fuchsin (WSAF) to pull out of the collagen with the 5% Phosphotungstic Acid (PA) or 1% Phosphomolybdic acid (PM) Acid. I have tried increasing the Bouin’s initial fixation (max 2 hrs 50*C), diluting the standard WSAF solution by 50% (1 dip) and taking the PA or PM up to 1 hr, yet there is always a lot of red still left in the collagen, in some regions as strong as the muscle (which I am sure are not muscle or dense cells). I see virtually no change with increased PA or PM time. As I have aorta in my samples I can’t just leave out the muscle stain. I would be very grateful for your insights into anything I could try to get clean collagen and stained muscle in the MP stain. Why might my method not be working? Is there something I can substitute for the WSAF that might be appropriate? Thank you very much for you help, Krista _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet