Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 34

In an examination of synovial fluid under compensated polarized light, rhomboid-shaped crystals are observed.What color would these crystals be when aligned parallel to the slow vibration?

A. White

B. Yellow

C. Blue

D. Red

Step 1 of 2

Crystal color:

The crystals “monosodium urate (MSU)” and “calcium pyrophosphate dihydrate (CPPD)” are having different linear structures of molecules.

• Because of different linear structure, the crystals are aligned with slow vibration to determine the color produced by each crystal.

• The molecules in MSU crystal moves parallel to the axis of crystal, and when crystals are aligned in slow vibration, it produces “yellow” color.

• The molecules in CPPD crystal are moves perpendicular to the axis of crystal, and when aligning the crystals in slow axis of compensator, it produces “blue” color.

Therefore, when rhomboid shaped crystals are seen in polarized light, the crystals would be “yellow” color when they are aligned parallel to slow vibration. Hence, the correct answer is option .