PAS x40 - RCPA

Examination of Masson stains:• Masson’s stain is a trichrome stain used todemonstrate connective tissue– nuclei are blue-black– muscle is red– collagen, reticulin, and basement membranes areblue/green– elastin is pale red– fibrin is red– deposits are red– red cells are red– mitochondria are red• use it to– assess interstitial fibrous tissue– look for foci of fibrinoid necrosis– look for deposits with high dry or oil immersion lens