Human Jo-1 Ab ELISA kit is intended for detecting in-vitro quantitative concentrations of IgG autoantibodies to Jo-1 antibody (Jo-1 Ab, Jo-1 IgG) in human plasma and serum. This assay has a minimum analytical sensitivity limit of 1.0 U/ml.


Jo-1 (also known as histidyl tRNA synthetase) belongs to the family of amino acyl-tRNA synthetase enzymes which can be found in all nucleated cells. Jo 1 antibodies are important markers for the disease polymyositis (usually in myositis patients who also have interstitial lung disease). They are able to bind to conformational epitopes of the enzyme protein and result in inhibiting its catalytic activity. Jo1 is also referred to as an extractable nuclear antigen and can be detected using and ENA screen.

It is found in over 25% of cases of polymyositis and also displays a good correlation with pulmonary fibrosis being present. Between 20–40% of polymyositis are found to be positive for Jo-1 antibodies, with majority also displaying interstitial lung disease, HLA-DR3 and HLA-DRw52 markers and these are often   collectively known as Jo-1 syndrome.


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: Consisting of 12 modules of 8 wells, highly purified Jo-1 is bound to microwells.
  • Calibrator A-F: Concentrations 0, 12.5, 25, 50, 100, 200 U/ml, made up from human Jo-1 antibody.
  • Control Positive and Control Negative: Containing human anti Jo-1 in a serum/buffer matrix.
  • Sample Buffer P (5x).
  • Enzyme Conjugate: Contains anti-human IgG antibodies, HRP labelled.
  • TMB Substrate.
  • Stop Solution.
  • Wash Buffer (50x Conc.).
  • Instruction For Use.
  • Certificate Of Analysis.


The minimum detection sensitivity level of human Jo-1 IgG autoantibodies (Jo-1 antibody, Jo-1 Ab, Jo-1 IgG) using current Jo-1 antibody ELISA kit was 1.0 U/ml. The dynamic range for this assay is 12.5 – 200.0 U/ml.


– Jo-1 Antibody: ELISA
– Measuring Range: 0 – 200 U/ml
– Expected Values: Cut-Off 25 U/ml
– Results Interpretation: Negative: < 15 U/ml, Borderline: 15 – 25 U/ml, Positive: > 25 U/ml
– Linearity: 96 – 105%
– Limit Of Detection (LOD): Functional sensitivity was determined to be 1 U/ml
– Intra Assay Precision: 3.2 – 5.5%
– Inter Assay Precision: 1.0 – 5.0%
– Interfering Substances: None
– Clinical Diagnosis: Sensitivity (34.1%), Specificity (96.3%), Overall agreement (75.2%).


  1. The role of Jo-1 in the immunopathogenesis of polymyositis: current hypotheses. Curr Rheumatol Rep. (2003) 5 (6): 425-30. Review. Ascherman D.P.
  2. Characterization and peripheral blood biomarker assessment of anti-Jo-1 antibody-positive interstitial lung disease. Arthritis Rheum. (2009) 60 (7): 2183-92. Richards T.J., et al.
  3. [Anti-Jo-1 autoantibodies (anti-histidyl tRNA synthetase autoantibodies)]. Nihon Rinsho. (1999) 57 Suppl: 431-4. Review. Japanese. Hirakata M. and Mimori T.
  4. Myopathy with anti-Jo-1 antibodies: pathology in perimysium and neighbouring muscle fibres. J Neurol Neurosurg Psychiatry. (2000) 68 (4): 472-8. Mozaffar T. and Pestronk A.
  5. Role of Jo-1 in the Immunopathogenesis of the Anti-synthetase Syndrome. Curr Rheumatol Rep. (2015) 17 (9): 56. Review. Ascherman D.P.


  • Full Name: Jo-1 Ab ELISA Kit
  • Reactivity: Human
  • Sample Type: Serum, Plasma
  • Sensitivity: 1.0 U/ml



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