(1992) Peter Gill at the home office of the Forensic Science Service, with a sample from the extraction procedure. Later it will be analyzed for a DNA profile. DNA consists of two sugar- phosphate backbones, arranged in a double helix, linked by nucleotide bases. There are 4 types of base; adenine (A), cytosine (C), guanine (G) and thymine (T). Sequences of these bases make up genes, which encode an organism's genetic information. DNA Fingerprinting. MODEL RELEASED
