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HelpTest Code C4 C4 Complement, Antigen, Serum or Plasma
Additional Codes
| Epic Order Code: | LAB151 |
| Sunquest Order Code: | C4 |
Specimen Required
| Container Type: |
Optimal: Inpatient: Mint STAT: Mint Outpatient: Gold Acceptable: Red Top or Green Lithium Heparin.
|
| Optimal Collection Volume: |
4.5 mL; Full Tube |
| Collection Instructions: |
Gently invert sample 5-6 times after collection. |
| Processing Instructions: |
1. Allow serum sample to clot for 30 minutes. 2. Centrifuge specimen within 2 hours of collection. 3. Specimen tubes without a gel barrier should have the serum or plasma aliquoted to a false bottom container after centrifugation. 4. Keep serum/plasma refrigerated until testing can be performed. |
Useful For
This assay is useful in assessing disease activity in a number of inflammatory processes such as systemic lupus erythematosus (SLE), proliferative glomerulonephritis, or rheumatoid arthritis.
Method Name
Immunoturbidimetric assay
Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum* | Refrigerated | 8 days |
| Ambient | 2 days | |
| Frozen | 3 months |
*Note: Heparinized plasma in gel separator tubes is less stable than serum and is only suitable for add-on testing up to 2 days following sample collection.
Rejection Due To
| Hemolysis | Mild OK; Moderate OK; Gross Reject |
| Lipemia | Mild OK; Moderate OK; Gross Reject |
| Icterus | Mild OK; Moderate OK; Gross Reject |
| Other | N/A |
Post Processing Specimen Type
Preferred: Serum
Alternate: Plasma
Specimen Minimum Volume
Collecting minimum volumes can result in a need for sample recollection, and/or a delay in results. Minimum volumes are subjective and cannot account for all aspects of specimen and testing needs. Refer to the Specimen Required section for optimal volumes for laboratory specimens. Contact the Bronson Laboratory if complex collection exceptions occur that require more information.
| Minimum Volume: | 0.5 mL whole blood, 0.25 mL serum or plasma |
| Neonate Volume: | 1 microtainer (400-600 uL) |
Performing Laboratory
Bronson Laboratory, Chemistry - Kalamazoo
Day(s) Performed
24/7
Reference Values
| Test ID | Reference Range | Units |
|---|---|---|
| C4 | 10-40 | mg/dL |
LOINC Code Information
4498-2
CPT Code Information
86160
Sample Retention Time
7 days