Graphically encoded suspension array for multiplex immunoassay and quantification of autoimmune biomarkers in patient...

In precision medicine, clinical decisions and pharmaceutical evaluations tends to be made upon parallel analysis of multiple protein biomarkers. Currently, the growing needs of high-throughput multiplex immunoassay is partially satisfied by spectrally encoded bead flow suspension arrays and other platforms, yet there is still room for progress in terms of encoding capacity, decoding accuracy, ease-of-manufacture/operation, and cost-effectiveness, for which graphical suspension arrays could make substantial contributions. Here we described a suspension array system made up of graphically encoded silica particles, an automated microplate imager and an in-house data processing program. The micro-fabricated, highly uniform planar particles provide a code space of 128-plex with further extendibility. The derived multiplex immunoassay reaches sub-picogram per milliliter sensitivity level (lowest LoD = 80 fg/ml) with wide dynamic range, as well as high precision and accuracy. The potential of clinical diagnostics was demonstrated by parallel measurement of three serum biomarkers for type 1 diabetes patients. Importantly, use of standard microplates as assay vessel extends its power to high-throughput applications, such as disease screening or drug discovery.