Genetic research, conceptual computer artwork. At right is a double helix of deoxyribonucleic acid (DNA) consisting of nucleotide base sequences. DNA has four bases: adenine (A), thymine (T), cytosine (C) and guanine (G). Sequences of triplets of these bases code for different amino acids, the building blocks of proteins. At upper right is a protein array chip, used to analyse and identify which proteins are being produced by a cell at different times.