Abstract: A method for the in vitro biosynthesis of proteins in native conformation which improves the technique which is well known in the art by immobilizing on the surface of an affinity matrix at discrete locations a ligand for which the protein being synthesized has an affinity and adding to the reaction mixture said affinity matrix having said immobilized ligand so that each molecule that is in the process of folding into a functional protein molecule may bind an immobilized ligand and be kept separated from other protein molecules as the folding proceeds. The technique works with either a batch method or a continuous method.