A process is disclosed by which a polynucleotide is directly synthesized from the peptide or protein that it encodes without the need for sequencing (or sequence analysis) of the peptide or protein. Information contained in the sequence of the peptide or protein is directly coupled, by the process of reverse translation, to the synthesis of the polynucleotide. The usefulness of reverse translation is that it facilitates the amplification of information held in the amino acid sequence (the primary structure) of an unknown protein or peptide. Amplification is useful for, among other things, the identification and/or scientific investigation of the peptide or protein.