IgM: Immunoglobulin M Class

Properties of IgM

Human IgM (immunoglobulin M)  is expressed on the surface of immature and mature B cells as monomers. IgM is the third most abundant human immunoglobulin.

IgM is also the first human immunoglobulin to be made by a fetus and virgin B cells which are challenged with antigen.

IgM is a strong complement activator and agglutinator due to its pentameric structure and binds fragment crystallization (Fc) receptors.

IgM
Heavy chain	μ
Light chain	κ or λ
Molecular formula	(μ2κ2)5 or (μ2λ2)5
Valency	10
Structure	Pentamer
Abundance in serum (in relation to total immunoglobulins present)	6%
Carbohydrate content	12%
Concentration in serum	0.5 - 2.0 mg/ml
IgM subclasses	None
Heavy chain MW (kDa)	70
Light chain MW (kDa)	23
Total MW (kDa)	970
Distribution	Mainly intravascular
Function	Primary response antibody

IgM Antibodies

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

Related 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 Antibodies (Immunoglobulin A)
• IgD Antibodies (Immunoglobulin D)
• IgE Antibodies (Immunoglobulin E)
• IgG Antibodies (Immunoglobulin G)

Associated Secondary Antibody Reading

• Learn about Secondary Antibody Specific Binding Locations
• Secondary Antibodies - Learn how to optimize your experiments