Adenovirus particles. Coloured transmission electron micrograph (TEM) of adenovirus particles. Each particle consists of an icosahedral protein coat (capsid, bright green) surrounding double stranded deoxyribonucleic acid (DNA), the virus' genetic material. The capsid has a glycoprotein fibre projecting from each of its apexes that aids attachment of the virus to its host cell. Adenoviruses most commonly cause respiratory disease in humans, but can also cause genitourinary diseases and gastroenteritis. These viruses have also proved successful for use as vectors in gene therapy and DNA vaccination. Magnification: x133,000 when printed 10 centimetres high.