Joint Fluid Analysis Guide

Monosodium Urate (MSU) crystals appear as negatively birefringent needle shaped crystals under red compensated polarized light microscopy. Appearance of a typical MSU fluid (white arrow shows orientation of red compensator):

Close-up View: ..........

MSU Tophus:

Calcium Pyrophosphate Dihydrate (CPPD) crystals appear as positively birefringent rhomboidal crystals under red compensated polarized light microscopy.  Appearance of a typical CPPD fluid (white arrow shows orientation of red compensator):

	Close-up View:

Cholesterol crystals appear as positively birefringent planar crystals with notched corners under red compensated polarized light microscopy. 

Lipid Liquid crystals appear as positively birefringent tiny spheres under red compensated polarized light microscopy.