Gene therapy offers to beat hepatitis B virus by muting its DNA

The hepatitis B virus mainly infects liver cells. After entering a cell, the virus’s DNA serves as the template to make new viral particles. | Photo Credit: U.S. CDC In 1904, two scientists, Henry Wheeler and Treat Johnson, synthesised a variant of cytosine, one of the building blocks of DNA, in the laboratory.The variant they synthesised contained a chemical tag called a methyl group (-CH3) attached to cytosine, so they called it 5-methylcytosine. Their motivation for doing so was based on the observation that two other building blocks of DNA and its chemical cousin RNA, called thymine and uracil, differed only by the presence of a methyl group. Published - October 29, 2026 08:00 am IST