IgG: Immunoglobulin G Class

Author: Misha Rahman, Ph.D.

Human IgG (immunoglobulin G) is expressed on the surface of mature B cells and is the most prevalent Ig in serum and the major Ig in extravascular spaces. IgG1, IgG2 and IgG3 are complement activators, with IgG3 being the strongest.

Human immunoglobulin subclasses IgG1 and IgG3 tend to strongly bind fragment crystallization (Fc) receptors, whereas subclasses IgG2 and IgG4 bind weakly. IgG is also the only human immunoglobulin to pass from mother to fetus to transfer immunity.

It should be noted, the human immunoglobulin subclass IgG2 does cross the placenta, but it does so weakly.

IgG
Heavy chain	γ
Light chain	κ or λ
Molecular formula	γ2κ2 or γ2λ2
Valency	2
Structure	Monomer
Abundance in serum (in relation to total immunoglobulins present)	80%
Carbohydrate content	3%
Concentration in serum	10 - 16 mg/ml
IgG subclasses	IgG1	IgG2	IgG3	IgG4
Heavy chain subclasses	γ1	γ2	γ3	γ4
Heavy chain MW (kDa)	50	50	60	50
Light chain MW (kDa)	23	23	23	23
Total MW (kDa)	150	150	170	150
Distribution	Intravascular and extravascular
Function	Secondary response antibody

Antibodies for IgG

Bio-Rad offers a range of human immunoglobulin antibodies for the IgG isotype. In addition to human, we also offer IgG antibodies for a wide range of other target species. Below you will find a list of all of our IgG antibodies. Use the buttons/filters to identify the antibody that fits your exact requirements.

Further Reading

For a full overview of Immunoglobulin classes please visit our Immunoglobulins Classes / Sub-classes page. Alternatively you can view the following individual types:

• IgA | Immunoglobin A
• IgD | Immunoglobin D
• IgE | Immunoglobin E
• IgM | Immunoglobin M