Molecular screening on a chip by DNA-displayed protein microarray

Self-assembled and spatially addressable protein microarrays are poised to become a central proteomics technology. However, it has been burdened with issues of reproducibility and standardization mainly due to the less availability of functionalized surface chemistry. Here, a microintaglio printing-based system is described that relies on coupling cDNA display technique with scaffolded DNA origami to print in situ-synthesized protein microarray on gold surface. A microarray of genotypes encoding the green fluorescent protein variants was patterned on gold-thiol surface using a three-way junctions (TWJs) formed from two single-stranded oligonucleotides with self-complementary sticky ends and a PDMS micromold comprising an array of uniformly arranged 4 μm-diameter holes at a density of 10,000 per mm 2