This negative-stained transmission electron microscopic (TEM) image revealed the presence of numerous hepatitis B virus (HBV) virions, also known as Dane particles. HBV contains a genome of DNA, and is a member of the family of viruses known as Hepadnaviridae. Attacking the liver, this virus causes an infection that can be lifelong. Liver infection, known as hepatitis, can lead to liver scarring, known as cirrhosis, liver cancer, liver failure, and death. Hepatitis B vaccine is available for all age groups, to prevent hepatitis B virus infection.