Anti-dsDNA IgG ELISA Kit (Anti-Double Stranded DNA)

INTENDED USE

Human anti-dsDNA IgG ELISA kit is a procedure for measuring in vitro quantitative levels of anti IgG autoantibodies to anti double stranded DNA (anti ds-DNA IgG, anti-dsDNA IgG) using human plasma or serum. This assay has a minimum analytical sensitivity limit of 1.0 U/ml.

BACKGROUND

Anti dsDNA antibodies are members of the anti-nuclear antibodies (ANA) and their main target antigen is double stranded DNA. They are linked to systemic lupus erythematosus (SLE) and if the disease is active then this leads to high levels of anti-DNA antibodies being found. In patients that have lupus nephritis, a high amount of double stranded DNA is associated with ongoing damage and inflammation to the kidneys. Patients with rheumatoid arthritis develop dsDNA antibodies and these are linked to the treatment undertaken. Many assay formats have been used to detect and quantify anti dsDNA antibodies (such as polyethylene glycol assay, microarrays, flow cytometry, Farr assay and EIA/ELISA).

CONTENT

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 each, human recombinant double stranded DNA (dsDNA IgG) is bound to microwells.
• Calibrator A-F: Concentration 0-200 U/ml.
• Control Positive and Control Negative: Containing anti dsDNA IgG antibodies in a serum/buffer matrix.
• Sample Buffer (5x).
• Enzyme Conjugate: Contains anti-human IgG antibodies, HRP labelled.
• TMB Substrate.
• Stop Solution: Contains acid.
• Wash Buffer (50x).
• Instruction for Use.
• Certificate of Analysis.

SENSITIVITY

The minimum detection sensitivity level of human IgG antibodies against anti-dsDNA IgG (anti double stranded DNA antibodies, anti dsDNA IgG) using current anti-dsDNA IgG ELISA kit was 1.0 U/ml. The dynamic range for this assay is 12.5 – 200.0 U/ml.

ASSAY CHARACTERISTICS

– Expected Values: Cut-off 20 IU/ml for samples from healthy blood donors.
– Results Interpretation: Negative: < 20 IU/ml,  Positive: ≥ 20 IU/ml.
– Linearity: 86 – 108%
– Limit Of Detection (LOD): Functional sensitivity is 1 IU/ml.
– Intra Assay: 3.1 – 6.4%
– Inter Assay: 5.2 – 12.4%
– Interfering Substances: None
– Clinical Diagnosis: Sensitivity (81.2%), Specificity (98.6%), Overall agreement (88.6%).

REFERENCES

1. Evaluation of a high avidity anti-dsDNA IgG enzyme-linked immunosorbent assay for the diagnosis of systemic lupus erythematosus. Int J Clin Exp Pathol. (2011) 4 (8): 748-54. Suh-Lailam B.B., et al.
2. Violation of an evolutionarily conserved immunoglobulin diversity gene sequence preference promotes production of dsDNA-specific IgG antibodies. PLoS One. (2015) 10 (2): e0118171. Silva-Sanchez A., et al.
3. Light chain determines the binding property of human anti dsDNA IgG autoantibodies. Biochem Biophys Res Commun. (2000) 271 (1): 240-3. Suzuki M., et al.
4. The antigen-binding fragment of anti-double-stranded DNA IgG enhances F-actin formation in mesangial cells by binding to alpha-actinin-4. Exp Biol Med (Maywood). (2012) 237 (9): 1023-31. Zou X., et al.
5. Significant differences in the analytic concordance between anti-dsDNA IgG antibody assays for the diagnosis of systemic lupus erythematosus–implications for inter-laboratory testing. Clin Chim Acta. (2011) 412 (11-12): 1076-80. Chiaro T.R., et al.

ADDITIONAL INFORMATION

• Full Name: Anti-dsDNA IgG ELISA kit (Anti-Double Stranded DNA)
• Reactivity: Human
• Sample Type: Plasma, Serum
• Sensitivity: 1.0 U/ml

OTHER RELATED ELISA KITS

• Anti-dsDNA IgA ELISA Kit
• Anti-dsDNA IgM ELISA Kit
• Anti-dsDNA Screen ELISA Kit