Anti-DNA binding activity in systemic lupus erythematosus, rheumatoid arthritis, and normal subjects.

rest were considered normal. It is well established that the abnormal binding of nDNA by serum antibody has a greater sensitivity than the lupus erythematosus cell phenomenon, and higher specificity than the antinuclear antibodies test, but both of these are used more frequently than the anti-DNA test as a confirmatory test for SLE. The Amersham kit contains all the reagents and instructions necessary to allow the nDNA assay to be performed in any laboratory with a gamma counter. Contrary to several studies citing the lack of specificity of the radioimmunoassay methodology for detection of antibodies to native deoxyribonucleic acid, the nDNA antibody assay kit by Amersham has proved to be both specific (97%) and sensitive (89%) (Table 1). If only for these reasons alone, it appears to be an excellent method for a routine clinical laboratory.