In every DNA-based organism, genetic information is represented by a four-letter genetic alphabet composed of deoxyadenosine (dA), deoxyguanosine (dG), deoxycytidine (dC), and deoxythymidine (dT) . The storage and retrieval of this information depend on the formation of two base pairs, (d)A-dT/U and (d)G-(d)C. Synthetic biology , which emerged over a century ago, aims to create new biological forms with potential applicability towards biomedical and bio engineering fields . One promising approach to achieving this goal is to expand the amount of information that can be stored and retrieved in a cell . As a result, scientists have dedicated considerable effort over the last decade to discovering a fifth and sixth nucleotides that can form a third, unnatural base pair (UBP) with increased functionality that can be orthogonally replicated in DNA . This would also expand the usefulness of nucleic acids for biological and biotechnological applications.