Complement, Total (CH50)
Also known as: Hemolytic Complement
Use
Total complement (CH50) measures the overall activity of the classical complement pathway. Decreased values are observed in complement factor deficiencies and in active immune complex–mediated diseases such as systemic lupus erythematosus (SLE). It is a first‑tier screening assay for classical complement pathway integrity.
Special Instructions
Avoid hemolysis; separate serum and freeze immediately after centrifugation. Separate specimens should be submitted when multiple tests are ordered.
Limitations
CH50 assesses only the classical pathway (C1–C9) and may remain normal even when individual components such as C3 or C4 are significantly reduced. It is insensitive to alternative pathway defects. Individual complement components may be needed for further evaluation.
Methodology
Other
Biomarkers
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Red‑top tube or serum separator tube
Collection Instructions
Allow specimen to clot (15–30 min), centrifuge, separate serum, freeze immediately, submit frozen in plastic vial
Storage Instructions
Frozen
Causes for Rejection
Gross hemolysis; lipemic; non‑frozen specimens
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 14–30 days |