Genetic research. Helices of DNA (deoxyribonucleic acid) over a DNA autoradiogram. DNA consists of a helix formed by twisting sugar-phosphate strands joined by pairs of four types of nucleotide base (red, yellow, green and blue). The bands (black) of the autoradiogram reveal the genetic data encoded in a sample of DNA (deoxyribonucleic acid). The bands correspond to the nucleotide bases in DNA, and the banding pattern shows the sequence of the bases. It is this sequence that forms a genetic code that is unique for every individual. DNA is a fundamental molecule that controls the development and functioning of every living organism.