Test Code
IGGSP (1623)

Quest Code

CPT Codes
82784, 82787 (x4)

Immunoglobulin G Subclasses 1, 2, 3, 4 and Total IgG

Preferred Specimen
2 mL serum 

Minimum Volume
1 mL

Transport Temperature
Refrigerated (cold packs)

Specimen Stability
Room temperature: 72 hours
Refrigerated: 10 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Lipemia


Setup Schedule
Set up: Tues-Sat; Report available: 1-3 days

Reference Range
See individual tests

Clinical Significance
Assess humoral immunity. Immunoglobulin G (IgG) is the most abundant immunoglobulin of extravascular liquids (65%) and of serum (70-75%). Antibodies of the IgG class are produced in response to most bacteria and viruses. IgG consists of two heavy and two light chains and contains less than 3% carbohydrate. IgG has four subclsses: IgG1, IgG2, IgG3, and IgG4. Both IgG1 and IgG3 bind firmly to the Fc receptors of phagocytic cells, activate killer monocytes (K cells), and cross the placenta.

Performing Laboratory
Quest Diagnostics Nichols Institute
27027 Tourney Road
Valencia, CA 91355-5386

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.