IgA: Immunoglobulin A Class

Author: Misha Rahman, Ph.D.

Human immunoglobulin A (IgA) is the second most common human immunoglobulin in serum. It is secreted in milk and is also the most prevalent lg in secretions (e.g. tears, saliva and mucous).

IgA is resistant to digestion and can activate the complement pathway when aggregated. It should also be noted both subclasses of IgA (IgA1 and IgA2) bind fragment crystallization (Fc) receptors.

IgA
Heavy chain	α
Light chain	κ or λ
Molecular formula	(α2κ2)n or (α2λ2)n
Valency	2, 4, 6 or 8
Structure	Monomers to tetramers (trimers and tetramers are rare, dimers are more common)
Abundance in serum (in relation to total immunoglobulins present)	13%
Carbohydrate content	10%
Concentration in serum	1.0 - 4.0 mg/ml
IgA subclasses	IgA1		IgA2
Heavy chain subclasses	α1		α2
Heavy chain MW (kDa)	55		55
Light chain MW (kDa)	23		23
Total MW (kDa)	160 (serum monomer)		160 (serum monomer)
	600 (secretory tetramer)		600 (secretory tetramer)
Distribution	Intravascular and secretions
Function	Protects mucous membranes

Antibodies for IgA

Bio-Rad offers a range of human immunoglobulin antibodies for the IgA isotype. In addition to human, we also offer IgA antibodies for a wide range of other target species. Below you will find a list of all of our IgA 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:

• IgD | Immunoglobin D
• IgE | Immunoglobin E
• IgG | Immunoglobin G
• IgM | Immunoglobin M