image

Adenoviruses. Coloured transmission electron micrograph (TEM) of a cell infected with adenovirus particles (red spheres). Each virus consists of an icosahedral protein coat (capsid) surrounding double stranded deoxyribonucleic acid (DNA), the virus' genetic material. 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: x66,500 when printed 10 centimetres tall. (KEYSTONE/SCIENCE PHOTO LIBRARY/EYE OF SCIENCE/SCIENCE PHOTO LIBRARY)