Picrosirius stain was used for Paracoccidioides brasiliensis in formalin-fixed human tissue. By common light microscopy the fungus shows a red peripheral band and on polarization microscopy, one or more birefringent green rings. Previous immersion in 1% sodium hidroxide solution enhances the staining and the birefringency of parasitic cells. The differentiation of the stained sections with 0,5% sodium hydroxide eliminates the birefringency of the collagen more rapidly than that of the paraeoccidioides.
Paracoccidioides brasiliensis; Paracoccidiodomycosis; Picrosirius; Histotechnology; Mycosis