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UW Health SMPH

UW Hospital and Clinics Lab Test Directory

Test Name: IgG

Test Code(s): IGG / XIGG

CPT Code(s): 82784

Methodology: Nephelometry

Clinical Significance: Measurement of IgG aids in the diagnosis of autoimmune diseases, lymphoid malignancies and immune deficiencies.

Days Performed: Daily, 24 hours.

Turnaround Time: Stat: 1 hour.
Routine: Up to 4 hours.


Specimen Requirements

Specimen: Blood

Collection Instructions: If there is the possibility that the patient has a cryoprotein, specimen MUST BE KEPT WARM UNTIL AFTER TESTING IS COMPLETE. Indicate specimen is to be drawn warm.

Collection Container: Preferred: Red cap with yellow ring (SST)
Also Acceptable: Red top

Collection Volume: Preferred: 3 mL
Pediatrics: 1 mL

Sample Analyzed: Serum

Volume Required: Preferred: 1 mL
Pediatrics: 0.3 mL

Specimen Processing: Centrifuge within 2 hours of draw. Transfer cell-free serum to plastic vial.  Refrigerate.  Freeze serum if not assayed within 72 hours.

IMPORTANT:
IF THE PATIENT HAS A CRYOPROTEIN, keep blood specimen at 37°C during entire processing procedure. Place collection tube in the 37°C incubator for two hours. Spin tube at 3000 rpm for 10 minutes at 37°C. Remove spun serum to labeled tube and forward to Chemistry Lab.

Specimen Transport: Transport specimen to UWHC Core Laboratory (B4/220). Transport with coolant pack if coming from outreach location. Transport frozen serum aliquot on dry ice to UWHC Core Laboratory (B4/220).

Important:
For samples on patients suspected of having a cryoprotein, specimen MUST be processed prior to transport if coming from outreach location. Transport specimens with coolant pack after processing is complete.

Unacceptable Criteria: Grossly hemolyzed specimens are not acceptable.

Stability: Refrigerated: 7 days
Frozen: 3 months at -20° C or below. Note: Avoid repeat freeze and thaw.


Interpretation

Reference Interval:
 Age:  mg/dL
 0 days-2 months   250-1200
 3 months- 23 months  286-1680
 24 months- 3 years  341-1960
 4 years-17 years  528-2190
 18 years and up  600-1600

 

           

           

Immunoglobulin G serum

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