Antibodies to the Scl-70 autoantigen also recognised as the enzyme topoisomerase 1, are highly specific for patients with Progressive Systemic Sclerosis (PSS, scleroderma) a chronic-inflammatory, autoimmune mediated disorder affecting connective tissue.
Intended use
Enzyme immunoassay for the detection of autoantibodies IgG against Scl-70.
Background
Progressive Systemic Sclerosis (PSS, scleroderma) is a chronic-inflammatory, autoimmune mediated disorder of the connective tissue. Its main manifestation is a thickening and hardening of the skin, but inner organs and blood vessels can be affected as well.
PSS patients present characteristic autoantibodies against a variety of nuclear proteins but almost always only one specificity at a time. These antibodies are valuable indicators of different PSS subsets and overlap syndromes with other systemic inflammatory disorders. Depending on the PSS variant, many patients carry antibodies directed against a basic nonhistone protein referred to as Scl-70 (scleroderma-associated 70 kDa autoantigen). It has been identified as DNA-topoisomerase I, a key nuclear enzyme that converts supercoiled DNA to the topological conformation required for DNA replication and transcription.
Scl-70 autoantibodies are considered as reliable marker of PSS. They indicate its severe course (diffuse scleroderma), typically involving lung, kidney or heart.
Technical information
The EULISA Scl-70 IgG is intended for the quantitative or qualitative determination of IgG antibodies in human serum, directed against Scl-70. The antigen used is a highly purified preparation of recombinant human DNA-topoisomerase I, expressed in the baculovirus system. The test is fast (incubation time 30-30-30 minutes) and flexible (break apart wells, ready-to-use reagents). Six calibrators allow quantitative measurements; a negative and a positive control are used to check assay performance.
Kit components and storage of reagents
Contents of the kit
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1 microwell plate, coated with Scl-70 antigen and hermetically packed in a foil laminate pouch together with a desiccant bag.
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Sample buffer, 100 mL, ready-to-use, orange coloured.
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Wash buffer, 100 mL, 10 x-concentrate, blue coloured.
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6 calibrators, 2.0 mL each, 0, 0.60, 2.0, 6.0, 20 and 60 U Scl-70 (IgG)/mL ready-to-use, gradually blue coloured.
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Negative and positive control, 2.0 mL each, ready-to-use, green and red coloured, respectively.
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Anti-human IgG HRP conjugate, 14 mL, ready-to-use, red coloured.
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Substrate solution, 14 mL, ready-to-use, colourless.
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Stop solution (0.5 M H2SO4), 14 mL, colourless, ready-to-use.
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Directions for use
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Lot-specific certificate of analysis
All kit components are stored at 2 - 8°C.
