Rheumatoid Factor IgG ELISA Kit (RF)

Full Name: Rheumatoid Factor IgG ELISA Kit (RF)
Reactivity: Human
Sample Type: Plasma, Serum
Sensitivity: 1.0 U/ml


Rhеumatoid factor (RF) was first discovеrеd in rhеumatoid arthritis, it is found as thе isotypе IgM but it can also bе in IgA, IgD, IgE and IgG form. It is found as an antibody dirеctеd against thе Fc portion of IgG, howеvеr, thеrе arе many diffеrеnt protеins which arе ablе to attach to spеcific sеctions of thе IgG-Fc molеculе. Thеsе factors arе usеful diagnostic markеrs for individuals that arе suspеct for rhеumatoid arthritis or any othеr rеlatеd autoimmunе conditions.

By idеntifying and mеasuring RF lеvеls in a patiеnt’s blood, hеalthcarе profеssionals can gain insights into potеntial undеrlying causеs and aid in making accuratе diagnosеs. Its prеsеncе or absеncе can providе critical information for hеalthcarе providеrs whеn еvaluating patiеnts with suspеctеd rhеumatic disеasеs.


Human rheumatoid factor IgG ELISA kit can be used for in-vitro quantitative analysis of IgG antibodies to rheumatoid factor (RF, RF-IgG, anti-rheumatoid factor IgG, rheumatoid factor IgG) in human serum and plasma. This assay has a minimum analytical sensitivity limit of 1.0 U/ml.


All reagents supplied need to be stored at 2 °C – 8 °C, unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.

  • Divisible Microplate: Fc fragments of highly purified human Immunoglobulin G are coated on to microwells.
  • Calibrator A-E: Concentration 0-500 U/ml, made up from rheumatoid factor in a serum/buffer matrix.
  • Control Positive and Control Negative.
  • Sample Buffer P (5x concentrated).
  • Enzyme Conjugate: Contains anti-human IgG antibodies, HRP labelled.
  • Substrate: Tetramethylbenzidin (TMB).
  • Stop Solution.
  • Wash Buffer (50x Concentrated).
  • Instruction For Use.
  • Certificate Of Analysis.


The minimum detection sensitivity level of anti-rheumatoid factor IgG (rheumatoid factor-IgG, RF-IgG) using current rheumatoid factor IgG ELISA kit was 1.0 U/ml. The dynamic range for this assay is 15.0 – 500.0 U/ml.


– Rheumatoid Factor IgG (RF-IgG): ELISA
– Measuring Range: 0 – 500 U/ml
– Limit of detection (LOD): 1 U/ml.
– Expected Values: Cut-off 20 U/ml for samples from healthy blood donors.
– Results Interpretation: Negative: < 20 U/ml, Positive: ≥ 20 U/ml.
– Intra Assay Precision: 5.5 – 7.4%
– Inter Assay Precision: 6.5 – 7.8%
– Linearity: 88 – 116%
– Interference: None.
– Clinical Diagnosis: Sensitivity (83.4%), Specificity (90.5%), Overall agreement (86.0%).


  1. [Rheumatoid factor and its related anti-IgG antibodies: the present state and perspective]. Nihon Rinsho Meneki Gakkai Kaishi. (2002) 25 (4): 319-29. Review. Japanese. Ota T.
  2. IgG rheumatoid factors and self-association of these antibodies. Clin Rheum Dis. (1985) 11 (3): 551-72. Review. Mannik M. and Nardella F.A.
  3. The structure of a human rheumatoid factor bound to IgG Fc. Adv Exp Med Biol. (1998) 435: 41-50. Review. Sutton B.J., et al.
  4. The effects of altered glycosylation of IgG on rheumatoid factor-binding and immune complex formation. Adv Exp Med Biol. (1995) 376: 155-60. Review. Soltys A.J., et al.
  5. [Immunological and serological tests for diagnosis of rheumatoid arthritis: IgG-RF]. Nihon Rinsho. (2005) 63 Suppl 1: 322-7. Review. Japanese. Miyashima S.
  6. Rheumatoid factor diversity. In Vivo. (1988) 2 (1): 73-7. Review. Koopman W.J. and Schrohenloher R.E.


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