Abstract: The present invention relates to a method for producing a protein array starting from DNA (or mRNA) in which a number of native, functional proteins, domains or peptides are produced in parallel by in in vitro synthesis using a cell free system for transcription and translation. The products are immobilised in a gridded format on a surface, using an isolation sequence tag incorporated into the proteins.

Abstract: The invention provides a method of displaying nascent proteins or peptides as complexes with eukaryotic ribosomes and the mRNA encoding the protein or peptide following transcription and translation in vitro, of further selecting complexes carrying a particular nascent protein or peptide by means of binding to a ligand, antigen or antibody, and of subsequently recovering the genetic information encoding the protein or peptide from the selected ribosome complex by reverse transcription and polymerase chain reaction (RT-PCR). The RT-PCR recovery step is carried out directly on the intact ribosome complex, without prior dissociation to release the mRNA, thus contributing to maximal efficiency and sensitivity. The steps of display, selection and recovery can be repeated in consecutive cycles. The method is exemplified using single-chain antibody constructs as antibody-ribosome-mRNA complexes (ARMs).