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HelpTest Code LAB71 Immunoglobulin G (IgG), Blood
Performing Laboratory
St. Louis Children's Hospital Laboratory - Chemistry
Specimen Requirements
Patient Preparation: None
Collection Container/Tube:
Preferred: Mint green-top Lithium Heparin (MNTGRN LiHep) tube
Acceptable: Green samplette/microtainer, plain red-top tube, Gold SST gel tube, or Lavender-top (EDTA) tube
Submission Container/Tube: If specimen is coming from outside facility and collected in a microtainer, plain red-top tube, or lavender-top tube aliquot processed sample into a plastic vial for transport (labeling with specimen type).
Specimen Collection Volume: 1.0 mL (minimum 0.6 mL)
Special Instructions: None
Sample Rejection
Mislabled or unlabeled specimens
Logistics
Test Availability: Monday-Sunday
Cut-off time: None, performed as received
Turnaround Time: Same Day; 2 hours from receipt in performing lab
Reference Values
Reference Interval:
| <3 weeks: | 300-500 mg/dL |
| 3 weeks-6 months: | 175-800 mg/dL |
| 6 mo-1 year: | 200-800 mg/dL |
| 1-4 years: | 300-1000 mg/dL |
| 4-10 years: | 400-1400 mg/dL |
| 10-18 years: | 500-1600 mg/dL |
| ≥ 18 years: | 700-1600 mg/dL |
Critical Value: None established
Methodology
Immunoturbidimetric Assay
Limitations
- As with other turbidimetric or nephelometric procedures, this test may not provide accurate results in patients with monoclonal gammopathy due to individual sample characteristics, which can be assessed by electrophoresis.
Additional Information
FOR SLCH CORE LABORATORY USE ONLY
Lab Processing Instructions: Centrifuge to separate. If specimen is collected in microtainer, plain red-top tube, or lavender-top tube aliquot sample into a Roche false-bottom tube for testing (labeling aliquot with specimen type).
Processed Volume: 0.3 mL plasma/serum
Analyte Stability:
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood (unprocessed) | Ambient | 8 hours |
| Plasma/Serum (processed) | Refrigerated (preferred) | 3 months |
| Ambient | 3 months | |
| Frozen | 6 months |
Test Classification and CPT Code
82784
LOINC
2465-3
Last Reviewed
06/2025