C4 Complement Component
Label Mnemonic: C4
Epic Lab Code: LAB151
Downtime Form: A-1a General Laboratory Requisition
Chemistry
6240 RCP
356-3527
Specimen(s):
Plasma
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
3 mL whole blood from light green top tube or 1 Microtainer®
Rejection Criteria:
Specimens collected in Sodium Citrate tubes.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
16-47 mg/dL
Comments:
Measures concentration by specific antibody. If cryoglobulin present or suspected, collect specimen as directed for 'Cryoglobulin, Serum'.
Test Limitations:
Criterion: Recovery within plus or minus 10% of initial value. Icterus: No significant interference up to an I index of 60 (approximate conjugated and unconjugated bilirubin concentration: 60 mg/dL). Hemolysis: No significant interference up to an H index of 500 (approximate hemoglobin concentration: 910 mg/dL). Lipemia (Intralipid): No significant interference up to an L index of 1000 (approximate triglycerides concentration: 2000 mg/dL). There is poor correlation between turbidity and triglycerides concentration. Rheumatoid factors up to 600 IU/mL do not interfere. No high-dose hook effect is seen up to a C4 concentration of 500 mg/dL. Monoclonal gammopathy sera of the IgA or IgM type can interfere with the C4 determination.
Methodology:
Immunoturbimetric
CPT Code:
86160