The Picro-Sirius Red Stain Kit (For Cardiac Muscle) is intended for use in the histological visualization of thin septa and collagen fibers. This modification of the Picro-Sirius Red stain eliminates the yellow cytoplasmic staining that can obscure thin collagenous septa. Using this procedure easily allows viewing of collagenous septa as thin as 0.2-0.5 microns. The PSR stain may be viewed using standard light microscopy or polarized light resulting in birefringence of the collagen fibers.

Light Microscopy
Collagen: Red
Septa: Red
Cytoplasm: Colorless to Slightly Yellow

Polarized Light Microscopy
Collagen Fibers: Yellow-Orange and Green Birefringence