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HelpTest Code LAB74 Immunoglobulin E (IgE), Blood
Performing Laboratory
St. Louis Children's Hospital Laboratory - Chemistry
Specimen Requirements
Patient Preparation: Do not collect from patients receiving treatment with omalizumab (Xolair)
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: Send to lab promptly.
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:
| <1 years: | ≤ 50 IUnits/mL |
| 1-3 years: | ≤ 100 IUnits/mL |
| 3-5 years: | ≤ 300 IUnits/mL |
| 5-8 years: | ≤ 400 IUnits/mL |
| 8-16 years: | ≤ 600 IUnits/mL |
| 16-18 years: | ≤ 500 IUnits/mL |
| ≥ 18 years: | ≤ 100 IUnits/mL |
Critical Value: None established
Methodology
Electrochemiluminescence immunoassay (ECLIA) sandwich principle
Limitations
- An interference was found for samples from patients treated with omalizumab (Xolair). Do not collect samples from patients under treatment with omalizumab or similar drugs containing anti-IgE antibodies.
- In rare cases, interference due to extremely high titers of antibodies to analyte-specific antibodies (such as HAMA), streptavidin or ruthenuim can occur.
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) | 7 days |
| Ambient | 8 hours | |
| Frozen | 6 months |
Test Classification and CPT Code
82785
LOINC
19133-0
Last Reviewed
07/2025