Test ID SFC Crystal Identification, Synovial Fluid
Useful For
Providing a definitive diagnosis for joint disease
Method Name
Compensated Polarized Light Microscopy
Includes cytospin prep.
Reporting Name
Crystal ID, Synovial FlSpecimen Type
Body FluidContainer/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Green top (heparin)
Specimen Volume: 2 mL
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Body Fluid | Refrigerated (preferred) | |
Ambient | 24 hours | |
Frozen |
Clinical Information
Birefringent crystals are found in the synovial fluid of >90% of patients with acutely inflamed joints.
Monosodium urate crystals are seen in gouty fluids and calcium pyrophosphate crystals are seen in chondrocalcinosis. The urates are usually needle-shaped, and the calcium crystals are often rhomboidal. Cholesterol crystals may also be observed.
Reference Values
None seen
If present, crystals are identified.
Cautions
Powdered anticoagulants such as oxalate are themselves crystalline; their use may cause confusion masking the presence of synovial fluid crystals definitive for the disease.
Day(s) Performed
Monday through Sunday; Continuously
Report Available
1 dayPerforming Laboratory

Test Classification
This test uses a standard method. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
89060