Fig. 1.

The principle of in situ peptide array synthesis and subsequent antibody binding analysis. A, digital micromirrors individually activate square features on the array by reflecting light on the photo-labile protecting groups of the previously incorporated amino acids. Repeated cycles of selective activation, addition of amino acids, and removal of excess amino acids enables parallel synthesis of peptides with unique sequences. B, schematic picture of incubation of the peptide array with the primary antibody and fluorophore-labeled secondary antibody. C, a scan image of a part of a planar ultra-dense peptide array in which the bright spots correspond to peptide features bound by antibodies.