C4 Complement Component
| Label Mnemonic: | C4 |
| Epic code: | LAB151 |
| Order form: | Laboratory Requisition |
| Supply order: | Supply Order Form |
| Billing: | Billing Policies |
| CPT code: | 86160 |
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
Sample Processing:
Centrifuge at a speed and time necessary to get barrier separation
of plasma/serum and cells within 1 hour of collection. Send specimen
in original tube. Do Not transfer to another tube.
Each sample must be labeled with at least TWO full patient identifiers (First/Last Name & DOB are sufficient for non-UIHC affiliated clients) to avoid sample rejection/delays.
Each sample must be labeled with at least TWO full patient identifiers (First/Last Name & DOB are sufficient for non-UIHC affiliated clients) to avoid sample rejection/delays.
Sample Storage:
Refrigerate.
All sample storage requirements are intended for delivery to UIHC within 24 hours of collection for testing. If samples won't arrive in this time period, please call the UIHC Core Lab for alternative storage/shipping instructions (319-356-3527).
All sample storage requirements are intended for delivery to UIHC within 24 hours of collection for testing. If samples won't arrive in this time period, please call the UIHC Core Lab for alternative storage/shipping instructions (319-356-3527).
Transport Instructions:
Place labeled specimen into zip-lock type biohazard bag; seal
bag.
Place completed requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.
Place completed requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.