Rheumatoid Factor IgG ELISA Kit


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.


Rheumatoid factor (RF) was initially identified in rheumatoid arthritis and they are referred to as an autoantibody. It is known as an antibody against the Fc portion of IgG, however, there are a number of RFs that are able to bind certain parts of the IgG-Fc. Even though it is mainly found in the IgM isotype form, rheumatoid factor can also be of IgA, IgG, IgD and IgE. RF and IgG can form immune complexes by joining together and this can contribute to disease processes. It can be used for the diagnosis and prognosis of the disease and is most often vital in evaluating patients which are a suspect for arthritis (in particular rheumatoid arthritis).


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.


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



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