Masson Goldner Trichrome Staining: A Technique to Visualize Collagen in Heart Sections for Cardiovascular Fibrosis Detection

1. Masson-Goldner Trichrome Staining

1. Make tissue sections from paraffin-embedded heart blocks with a manual microtome (thickness: 5 µm).
2. Stain one slide from each heart part for each rat (3 – 4 transversal sections per slide) with Masson-Goldner trichrome staining.
   1. Melt the slides at 60 °C in an oven. Under a fume hood, deparaffinize them in xylol twice for 10 min each. Rehydrate them in 100% ethanol, 95% ethanol, 70% ethanol, and distilled water for 3 min each.
   2. Fix them in Bouin solution overnight. Then, rinse them in running tap water for 10 – 15 min. Rinse them in distilled water. Incubate them in Mayer's hematoxylin for 3 min.
   3. Remove the slides and leave them in distilled water for 5 min. Then, incubate them in acid Fuchsin-Ponceau for 5 min. Rinse them in 1% acetic acid for 1 min.
   4. Next, incubate them in phosphomolybdic acid Orange G for 1 min. Rinse them in 1% acetic acid for 1 min, incubate them in light green dye for 10 min, and rinse them in 1% acetic acid for 1 min.
   5. Dehydrate them in 70% ethanol (30 sec), 95% ethanol (30 sec), and 100% ethanol (5 min). Put one drop of a resinous mounting medium on the tissue sections, cover them with coverslips, and let them dry.