Masson's Trichrome Stain

This method is used for the detection of collagen fibers in tissues such as skin, heart, etc. on formalin-fixed, paraffin-embedded sections, and may be used for frozen sections as well. The collagen fibers will be stained blue and the nuclei will be stained black and the background is stained red.

Fixation: 10% formalin or Bouin's solution

Result:
Collagen: blue
Nuclei: black
Muscle, cytoplasm, keratin: red