Abstract
A dual detection system for protein arrays is presented that combines label-free detection by optical interference with chemiluminescence. A planar protein array that targets hepatitis B surface antigen is developed. Surface densities for individual antibody spots are quantitated using optical interference prior to use. Target binding (10 ng/ml) is detected label-free. Target binding (1 ng/ml) is detected by both optical interference and chemiluminescence with the inclusion of secondary antibodies. Binding results using both methods are found to be directly proportion to the capture probe density measured initially. The dual detection system provides the analytical utility of optical interference detection with the established clinical utility of chemiluminescence detection.