A luminescent substrate was then added and arrays imaged with a charge-coupled device (CCD) chemiluminescence camera. Joos et al. demonstrated sensitive and specific detection of autoantibodies specific for many of the 18 antigens contained on the arrays. In particular, because the microassays contain serial dilutions of the various antigens, the signal intensities observed from serial dilutions of the immobilized antigen correlated well with serial dilutions of autoimmune sera. Another group adapted this method for autoantibody profiling using fluorescence-based detection systems [12]. The Authors constructed miniaturized auto-antigen arrays to perform multiplexed measurements of 196 distinct autoantibodies representing the most important markers of autoimmune rheumatic diseases. A secondary anti-human antibody conjugated to the Cy-3 fluorochrome was used to detect the binding between patient autoantibodies and the specific autoantigens attached on the array surface. According to the obtained results, the antigen arrays were four- to eight-fold more sensitive than conventional immunoassays (ELISA).