Specimen Requirements


Complement C4

Specimen Requirement

Collect SST or red top. Allow serum to clot at room temperature for 15 to 30 minutes, centrifuge, transfer 1.0 mL serum/plasma to a screw top transport tube, indicate sample type on tube and send. If collecting SST, send separated serum in the original collection tube.

Alternate Sample:
Green top lithium heparin or lavender EDTA




Room temp: 3 days, Refrigerated: 3 days, Frozen: 14 days

Reference Range

By Report*


1-2 days

Clinical Use

Quantitation of C4 is used to detect individuals with inborn deficiency of the factor or those with immunological disease in whom hypercatabolism of complement causes reduced levels. These diseases include lupus erythematosus, serum sickness, certain glomerulonephritides, chronic active hepatitis, and others.

Test Code