The complimentary strand of CTXAGGC is GAYTCCG. Scientists incorporates two synthetic DNA letters, called X and Y, along with the four natural ones, A, T, C and G, which means adenine, thymine, cytosine and guanine.
Moreover, a specialized bacterium is used to produce proteins, incorporating it to the artificial amino acid and are placed at precisely specified intervals along the protein sequence, obeying the code of the expanded DNA alphabet to create efficient and cheap drugs.