The Picro-Sirius Red solution finds application in histology, especially for the examination of collagenous fibers in tissue sections. It is particularly suitable for the visualization and quantification of collagenous connective tissue in various organs, such as liver, kidney and lung.

The chemical mode of operation is based on the combination of picric acid and Sirius Red F3B. Picric acid is a fixative that stabilizes tissue structures and facilitates the binding of Sirius Red F3B to collagen fibers. Sirius Red F3B, a synthetic azo dye, specifically binds to collagenous fibers and stains them red.

Compared to other staining methods for collagenous fibers, the Picro Sirius Red solution offers improved sensitivity and specific binding. These properties enable precise visualization of collagen structures, facilitating analysis and quantification of collagenous connective tissue in histological specimens. Another advantage of the Picro-Sirius Red solution is the ability to examine the staining under polarized light to obtain information about the spatial arrangement and organization of collagenous fibers. This contributes to a more comprehensive understanding of tissue architecture and possible pathological changes.