DNA autoradiogram. Conceptual computer artwork of a female face and lights, overlaid with a DNA autoradiogram. The bands on the autoradiogram give information about a DNA (deoxyribonucleic acid) sample. The bands represent the nucleotide bases of DNA, the sequence of which forms a genetic code that is unique for every individual. DNA controls the development and functioning of every living organism. The four bases that make up the code are adenine (A), guanine (G), cytosine (C) and thymine (T). The code can be transcribed as a sequence of letters representing these bases, as in the column at right.