Picrosirius red: a better polarizing stain

Abstract

Collagen is a part of the extracellular matrix proteins that form an integral part of the connective tissue stroma. Collagen plays an important role in maintaining the structural and functional integrity of tissue. Due to the arrangement of its fibers, it illustrates the phenomenon of birefringence that is enhanced by special stains like van Gieson and Picrosirius Red. The aims of the present study were to compare the polarizing properties, shelf life and staining intensity of both these connective tissue stains to ascertain which gave better and most cost-effective results. A retrospective study was conducted in the Department of Oral Pathology where histopathologically diagnosed cases of fibroma were selected. Consecutive sections of formalin fixed and paraffin embedded tissues were stained with Picrosirius Red and van Gieson stains, respectively. This staining procedure was repeated on successive sections every 15th day for a period of 6 months. The polarizing property and staining intensity of the new and the previously stained sections along with the shelf life of the staining solutions were simultaneously evaluated and revaluated each time and tabulated. The data obtained was analyzed by using independent t-test and chi-square test. After a period of six months, the polarization intensity and stability of Picrosirius red was found to be better than van Gieson and this could also be appreciated more clearly in the stained sections. The p value was also found to be statistically more significant with Picrosirius Red as compared to van Gieson. Picrosirius Red Stain is not only more stable but also has better polarizing properties, staining intensity, and a longer shelf life as compared to van Gieson.