Epitope Mapping by Printed Peptide Libraries

Affordable high-density peptide arrays are needed to routinely define the exact binding sites of antibodies. In terms of prize and density peptide arrays currently lag far behind oligonucleotide arrays that are available in densities exceeding 50.000 oligonucleotides per cm2. This is mainly due to the monomer-by-monomer repeated consecutive coupling of 20 different amino acids associated with the lithographic methods, which adds up to an excessive number of coupling cycles. The combinatorial synthesis of peptide arrays based on electrically charged solid amino acid particles circumvents this problem. A colour laser printer or a microchip consecutively address the different charged particles to a solid support, where a complete layer of solid amino acid particles is melted at once. This releases hitherto immobilized amino acids to couple all 20 different amino acids to the support in one single coupling reaction.