Chip printer

Lithographic methods allow for the combinatorial synthesis of >50.000 oligonucleotides per cm2, which revolutionized the field of genomics. High density peptide arrays promise to advance the field of proteomics in a similar way, but until recently were not available. This is mainly due to the monomer-by-monomer repeated consecutive coupling of 20 different amino acids associated with lithography, which adds up to an excessive number of coupling cycles. A combinatorial synthesis based on electrically charged solid amino acid particles resolves this problem. Here we report the manufacturing of a "chip printer" that could be used to consecutively address the different charged particles to a solid support, where, when completed, the whole layer of solid amino acid particles is melted at once. This frees hitherto immobilized amino acids to couple all 20 different amino acids in one single coupling reaction to the support. The method should allow for the synthesis of very high-density peptide arrays.