False-colour transmission electron micrograph of Hepatitis B virus (HBV) particles - the small red spheres and tubules. HBV causes acute & chronic forms of liver inflammmation. It appears in 3 structural forms: spheres 20 nanometres (nm) in diameter; tubules of similar diameter, and Dane particle spheres 40nm in diameter. HBV is transmitted in infected blood; symptoms develop after an incubation period of 1-6 months and include headaches, fever and jaundice. The presence of the Australia antigen in blood confirms the diagnosis. Magnification x16,000 at 6x7cm size.