The University of Iowa (UIHC)
Department of Pathology
LABORATORY SERVICES HANDBOOK


C4 Complement Component
Order Code: C4
Order Form: A-1a General Lab or IPR Req
  Chemistry
6240 RCP
356-3527
Specimen
Plasma
Collection Medium:
Plasma separator tube
Alternate
Collection Media:
Call laboratory for additional acceptable specimen collection 
containers.
Minimum:
5 ml whole blood from light green top tube
Rejection Criteria:
Specimens collected in Sodium Citrate tubes.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Analytic Time:
2 hours (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 or 1026 umol/l).

Hemolysis: No significant interference up to an H index of 900 
(approximate hemoglobin concentration: 900 mg/dl or 559 umol/l)

Lipemia (Intralipid): No significant interference up to an L index of 
1000 (approximate triglycerides concentration: 2000 mg/dl or 22.8 
mmol/l). There is poor correlation between turbidity and triglycerides 
concentration.

Rheumatoid factors up to 1200 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
 
See also:
Cryoglobulin, Serum

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Updated: 12/14/2006

Note: The information contained in this handbook is for use by personnel of University of Iowa Health Care. No other use is implied or intended.