C4 Complement Component

Label Mnemonic:	C4
Epic code:	LAB151
Downtime form:	Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

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