Total Complement (CH50)
CH50, Complement CH50, Total
Antrim #30240, EPIC: LAB7024, SOFT: CH50G
Specimen Collection Criteria
Collect: One plain Red-top tube. (Minimum Whole Blood: 2.0 mL)
Critical Frozen. Document the collection time on either the tube or requisition form and send specimen immediately for processing.
Physician Office/Draw Specimen Preparation
Let specimen clot 30-60 minutes at room temperature (20-26°C or 68-78.8°F) then immediately centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and freeze (-20°C/-4°F or below) immediately. (Minimum Serum: 0.5 mL)
Preparation for Courier Transport
Transport: Serum in a plastic transport tube, frozen (-20°C/-4°F or below). (Minimum Serum: 0.5 mL)
- Specimens collected in any tube other than a plain Red-top tube.
- Specimens not collected and processed as indicated.
- Specimens not received frozen from off-site areas/offices.
- Severely hemolyzed, lipemic or icteric specimens.
Let specimen clot 30-60 minutes at room temperature (20-26°C or 68-78.8°F) then immediately centrifuge to separate serum from cells. Freeze (-20°C/-4°F or below) immediately. (Minimum Serum: 0.5 mL)
Specimen Stability for Testing:
Serum Specimens (Pour-Overs)
Room Temperature (20-26°C or 68-78.8°F): Unacceptable
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): 14 days
Specimen Storage in Department Prior to Disposal:
Frozen (-20°C/-4°F or below): 7 days
Royal Oak Special Chemistry Laboratory
Results available within 3 business days.
Greater than or equal to 41.7 U/mL.
Liposome Immunoassay (The Binding Site SPAPLUS Analyzer)
Total Complement (CH50) is a functional assay that measures the activity of complement components C1 to C9 (i.e., the classical and terminal pathways). It does not measure the functional activity of the alternative pathway. If the Total Complement (CH50) measurement is zero or very low it is advisable to repeat the test to confirm the result. If the result is confirmed, the clinical presentation should be considered prior to further testing. If the patient exhibits recurrent neisserial infection, immunochemical determination of C5, C6, C7 and C8 is advised (or a functional assay for C5-C8). If the clinical problem is angioedema, initial studies should include C3, C4, C1 inhibitor (and possibly C1q and C2). Acquired disorders such as immune-mediated glomerulonephritis and other autoimmune disorders should direct testing towards C3 and C4.
Note: In order to assess the alternative complement pathway, the alternative pathway CH50 may be ordered (send-out test).
Special Chemistry Laboratory – RO
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