(1992) Nymsfield, England. Badger research center. Peter Mallinson takes sputum & blood samples studying the epidemiology of Tuberculosis in Badgers & how they spread it to cattle. Catheters are stuck down the badgers' throats, anesthetizing them, allowing researchers to take blood samples. By taking sputum and blood samples that are then DNA fingerprinted, researchers are able to study the epidemiology of tuberculosis in badgers and how they spread it to cattle. Animals were also weighed, ear tagged, and tattooed. 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.