Viral DNA research. Artwork of an enveloped virus behind a test tube containing a molecule of deoxyribonucleic acid (DNA). The virus consists of genetic material (DNA) inside an icosahedral protein coat (nucleocapsid), enveloped by other proteins. Viruses contain DNA or RNA (ribonucleic acid), never both. DNA consists of two strands (red and blue) twisted into a double helix. Between the two strands are nucleotide bases. DNA contains sections called genes, which encode an organism's genetic information.