English: The DNA and RNA viruses described in this study were classified by Baltimore group. A representative of each virus family and their structures are summarized in the figures. (A) Herpes simplex virus-1 is a member of Herpesviridae, classified to Baltimore group I possessing dsDNA as the genome in a nucleocapsid core enveloped by lipid membrane. (B) Hepatitis C virus and (C) Dengue virus are member of Flaviviridae, classified to Baltimore group IV possessing a (+) single-stranded RNA genome in the viral particle. (D) Influenza A virus is a member of Orthomyxoviridae, classified to Baltimore group V possessing eight (−)-strand viral RNA genomes in the viral particle. (E) Human immunodeficiency virus-1 is a member of Retroviridae, classified to Baltimore VI possessing two (+)-strand RNA genomes in a protein core in the viral particle.