A microarray enzyme-linked immunosorbent assay for autoimmune diagnostics

In order to quantify autoantibodies in the sera of patients with autoimmune disease, we have created a microarray-based immunoassay that allows the si multaneous analysis of 18 known autoantigens. The microarrays contain seria l dilutions of the various antigens, thereby allowing accurate determinatio n of autoantibody titer using minimal amounts of serum. The assay is very s ensitive and highly specific: as little as 40 fg of a known protein standar d can be detected with little or no cross-reactivity to nonspecific protein s. The signal intensities observed from serial dilutions of immobilized ant igen correlate well with serial dilutions of autoimmune sera. Miniaturized and highly parallelized immunoassays like these will reduce costs by decrea sing reagent consumption and improve efficiency by greatly increasing the n umber of assays that can be performed with a single serum sample. This syst em will significantly facilitate and accelerate the diagnostics of autoimmu ne diseases and can be adapted easily to any other kind of immunoassay.