1. An in vitro method of increasing reaction selectivity among a plurality of reactants in a nucleic acid-templated synthesis to produce, without the assistance of a ribosome, a reaction product that is not a nucleic acid, the method comprising the steps of: (a) providing (i) a template associated with a capturable moiety and comprising a first reactive unit associated with a first oligonucleotide comprising a predetermined codon sequence, (ii) a first transfer unit comprising a second reactive unit associated with a second oligonucleotide comprising an anti-codon sequence capable of annealing to said codon sequence, and (iii) a second transfer unit comprising a third reactive unit different from said second reactive unit associated with a third oligonucleotide without an anti-codon sequence capable of annealing to said codon sequence, wherein said second reactive unit and said third reactive unit are capable of reacting independently with said first reactive unit and said second reactive unit and said third reactive unit are capable of reacting with one another; and (b) mixing said template, said first transfer unit and said second transfer unit under conditions to permit annealing of said second oligonucleotide of said first transfer unit to said first oligonucleotide of said template thereby to enhance covalent bond formation between said second reactive unit and said first reactive unit to produce the reaction product relative to covalent bond formation between said third reactive unit and said first reactive unit.