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Test Code C3 or LAB152 C3 Complement, Serum or Plasma

Specimen Requirements

Container Type:

Optimal: Gold or Mint*

*For STAT requests

Acceptable: Red or Green

Optimal Collection Volume: 

4.5mL; full tube

Minimum Volume:
  • Adults: 1 mL whole blood
  • Neonates: 1 microtainer (400-600 uL)
Collection Instructions:

Gently invert the sample 5-6 times after collection.

Specimen Transport:

Refrigerate

Processing Instructions: 

1. If serum, allow the specimen to clot for 30 minutes.

2. Centrifuge specimen within 2 hours of collection.

3. After centrifugation, specimen tubes without a gel barrier should have the serum or plasma aliquoted to a false bottom container.

4. Keep the serum or plasma refrigerated until testing can be performed.

Specimen Stability

Specimen Type Temperature Time
Serum* Refrigerated 7 days
Room Temperature 4 days
Frozen 1 month

*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.

Specimen Rejection Criteria

Hemolysis Mild OK; Moderate OK; Gross Reject
Lipemia Mild OK; Moderate OK; Gross Reject
Icterus Mild OK; Moderate OK; Gross Reject
Other Quantity not sufficient

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.

Methodology

Roche Cobas - Immunoturbidimetric

Reference Ranges

86-184 mg/dL

Interpretive

A decrease in C3 levels to the abnormal range is consistent with disease activation in systemic lupus erythematosus.

 

Source: Mayo Medical Labs

Day(s) Performed

24/7

Expected TAT

Same day

Performing Laboratory

Bronson Laboratory, Chemistry - Kalamazoo

Sample Retention Time

7 days

CPT Code

86160

LOINC Code

4491-7