Where can I find the protein concentration?

The protein concentration of each product is listed on the Certificate of Analysis. This value is determined for each individual lot and reflects the actual concentration (mg/mL) of the material you received.

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What should I do if my product arrives warm, partially thawed, or damaged?

Please contact Athens Bioscience with your order number and lot number. Our technical support team will assist you promptly.

Where can I find the final buffer composition?

The final buffer formulation is provided on the Certificate of Analysis. This includes buffer components, pH, and whether the product was supplied as a liquid or lyophilized powder.

Rheumatoid Factor, Immunoglobulin M

Name: Rheumatoid Factor, Immunoglobulin M
SKU: 16-16-180603-250UL
Availability: InStock

RF-IgM

An autoantibody which targets the Fc region of IgG, forming immune complexes that drive inflammation. RF-IgM is present in about 70-80% of RA patients.

Purity: ≥95% (SDS-PAGE)

Source: Human Plasma

Molecular Weight: 970 kDa

Form: Liquid

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Product Description

Role of protein in biology

Rheumatoid factor IgM (RF-IgM) is an autoantibody produced by the immune system that targets the Fc region of immunoglobulin G (IgG), forming immune complexes that can drive inflammation. RF-IgM is the most clinically significant and commonly measured isotype among rheumatoid factors, present in approximately 70–80% of patients with rheumatoid arthritis (RA). Functionally, RF-IgM amplifies inflammatory responses by increasing the recruitment of IgG into immune complexes, which then stimulate macrophages to secrete proinflammatory cytokines such as TNF-α, IL-6, and IL-8, and enhance complement activation, contributing to joint inflammation and tissue damage in RA. High levels of RF-IgM are associated with more severe, progressive disease, greater joint destruction, and increased risk of extra-articular manifestations.

Common research uses

Beyond RA, RF-IgM can be elevated in other autoimmune diseases (e.g., Sjögren’s syndrome, systemic lupus erythematosus) and chronic infections (e.g., hepatitis C, endocarditis)2. Clinically, RF-IgM serves as a diagnostic and prognostic marker in RA and is used alongside anti-cyclic citrullinated peptide (anti-CCP) antibodies to improve diagnostic accuracy and guide disease management.

Common uses include IVD assay standards, calibrators and controls.