COMPLEMENT, TOTAL (CH50)
DRAW BLOOD IN A PLAIN RED-TOP TUBE. ALLOW BLOOD TO CLOT AT ROOM TEMPERATURE 60-65 MINUTES. CENTRIFUGE, SEPARATE AND SEND 1.0ml SERUM (0.5 ml MINIMUM) FROZEN ASAP IN A SCREW-CAPPED PLASTIC VIAL. INDICATE ON TRANSPORT TUBE “SERUM/RED TOP”.
REJECTION CRITERIA: ROOM TEMP OR REFRIGERATED SAMPLES, SST.
Frozen: 14 days
Deficient or decreased levels of serum complement activity of the classical pathway are associated with a number of diseases. A normal CH50 assay indicates that C1 through C9 are present and functional in the serum being tested. Although CH50 can be used to assess the integrity of the classical pathway, it must not be used as a sensitive test for in vivo complement fixation. In vitro degradation can also cause low CH50 activity.