P.T.A. – P.M.A. reagent is a component of Masson Trichrome and Masson-Goldner Trichrome staining kits. Both kits are used for visualization of muscles, collagen fibers, connective tissues, gametes, nuclei, neurofibrils, neuroglia, collagen, keratin intracellular fibrils and negative visualization of the Golgi apparatus. It is also used for visualization of increased collagen build up associated with functioning tissue being mistaken for scar tissue (liver sclerosis diagnosis), but also for differentiating smooth muscle fibers and collagens. Difference between Masson Trichrome and Masson-Goldner Trichrome is in staining collagen and mucus, which are stained blue with Masson Trichrome unlike Masson – Goldner Trichrome wherein these structures are stained green.