Fluorimetric method for the detection of anti-DNA antibodies in serum

A method for the detection of native anti-DNA antibodies in serum is described. The method is based on the reactivity of fluorescein isothiocyanate with DNA, forming a complex capable of combining with anti-DNA antibodies. The fluorescein content of the precipitated fluorescein-DNA anti-DNA complex is then measured in a fluorometer. The assay is accurate, highly reproducible, and inexpensive to perform. Comparative studies performed with the Farr assay show the fluorimetric method to be more sensitive in detecting anti-DNA antibodies in the serum of SLE patients.