Reexploring picrosirius red: A review

Picrosirius red stain has been increasingly used for collagen studies in dental and medical research. Sirius
red is an acidic dye which binds specifically to collagen and distinguishes type I and type III collagen fibres.
This review depicts earlier uses of picric acid, preparation of the picrosirus red stain, mechanism of action,
hazards and safety protocols of handling picric acid in laboratory.

Keywords: Birefringence, Collagen fibres, Picrosirius red stain, Polarized microscopy, Picric acid.