Critical ds-DNA-reactive antibodies for the diagnosis of systemic lupus erythematosus (SLE), appear to play a central role in the pathogenesis of tissues injury and are closely related to clinical activity. Its presence is also associated with active lupus and usually with immune complex glomerulonephritis. Antibodies against ds-DNA are directed against a phosphate-deoxyribose backbone of DNA molecule and seem to be generated due to preferential activation of specific B cells and are not simply due to the hyperactivity of the polyclonal B cells before the exacerbation of SLE.
Antibodies against ssDNA (nucleotide bases) are also common, most notably in ANAs that produce a homogeneous pattern in indirect immunofluorescence. Anti-ssDNA is also found in non-immune disorders, as well as in autoimmune diseases such as rheumatoid arthritis, SLE, and systemic sclerosis. However, autoantibodies against dsDNA when present in high concentration are virtually specific for SLE (> 90%).
Source of antigens and antibodies
dsDNA, native, has been specially purified from the calf thymus and tested by ELISA for reactivity with control DNA antibodies. It has a high molecular weight of 10-15 million Daltons. (41.9 mole% G_C and 58.1 mole A-T; an OD of 1.0 to 260 nm = 50 ug dsDNA). Supplied in PBS, pH 7.4, at 1 mg/ml (or see the conc. sp. lot on the vial). Store in – 20oC in aliquots of suitable size. If supplied in powder form then dissolve it in PBS or other buffers at 1 mg/ml or in the desired concentration. Do not freeze or thaw.
ELISA for the detection of antibodies against the DNA layer at 1 10 ugs/ml and detect with suitable mouse antibodies (# DNA11-M) or anti-rabbit DNA antibodies. This batch of dsDNA has been tested in ADI ELISA # 5110, 5120, 5130 and the coated dsDNA detected both IgG and IgM anti-dsDNA antibodies.
- Short term: unopened and undiluted vials for less than a week at 4oC.
- Long term: at –20 ° C or below in suitable aliquots after reconstitution. Do not freeze, thaw and store in operation, dilute solutions.
Stability: 6-12 months at –20oC or less.
Shipping: 4oC for solutions and room temperature for lyophilisates elements.