Complement, Total (CH50)

Test Code

CPT Codes

Preferred Specimen
1 mL serum

Minimum Volume
0.2 mL

Avoid hemolysis. Centrifuge serum specimens within 1 hour of collection. Immediately pipette serum into "sterile, plastic, screw-capped vial(s) and freeze solid" at -20°C or lower. Do not allow samples to thaw. With multiple tests, submit a separate tube for each test. Send frozen samples on dry ice to the laboratory. Do not submit the sample in a glass tube.

Transport Container
Plastic screw-cap vial

Transport Temperature

Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
CSF • Pleural fluid • Pericardial fluid • Synovial fluid • Received room temperature • Received refrigerated


Reference Range
31-60 U/mL

Clinical Significance
CH50 is a screening test for total complement activity. Levels of complement may be depressed in genetic deficiency, liver disease, chronic glomerulonephritis, rheumatoid arthritis, hemolytic anemias, graft rejection, systemic lupus erythematosis, acute glomerulonephritis, subacute bacterial endocarditis and cryoglobulinemia. Elevated complement may be found in acute inflammatory conditions, leukemia, Hodgkin's Disease, sarcoma, and Behcet's Disease.

Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.