C3 a1C/a1A

Category: Immunoglobulin/ Complement
Test Code: 405
Methodology: Nephelometry
Reference Range: 80-175 mg/L
Units: mg/dl
CPT Code: 83883
Schedule / Turnaround Time: Report availability is one week from the time of specimen receipt.
Specimen Requirements:

Specimen need not be refrigerated or frozen. Collect 2-3 ml of blood in a red top or serum separator tube. If possible, separate serum from clot and place into white tube provided with Immco Diagnostics’ collection kits. If separation facilities are not available, the blood can be sent in the tube used for collection.

Sample Stability:

Sample is stable at ambient temperature during shipment. If sample is stored prior to shipment, it is stable refrigerated (2-8˚C) up to five days and frozen (-20˚C or lower) up to one year.


Quantitation of C3 is used to detect individuals with inborn factor deficiency or those with immunologic disease in whom complement is consumed at an increased rate. These include lupus erythematosus, chronic active hepatitis, certain chronic infections, post streptococcal and membranoproliferative glomerulonephritis, and others.