Figure 3: Immunosignature array synthesis.

(a) Mask-based patterned synthesis of peptides was performed on 200-mm silicon wafers with thermal oxide coating, starting with an aminosilane–glycine monolayer and building peptides through cycles of patterned acid formation in a photoresist removing Boc groups from the N-terminal amines of nascent peptides and coupling of the next amino acid. (b) The wafer is diced into microscope slide-sized regions (75 × 25 mm), each of which contains 24 arrays of 300 and 30,000, 8-μm features. Samples can individually be applied to each array via a commercially available gasket system and scanned on a laser scanner. On the far right is an image of the array (at × 800 magnification) of serum applied to the array and detected with fluorescent secondary antibody.