Expansion of the Genetic Alphabet: Unnatural Nucleobases and Their Applications

1Department of Chemistry, Indian Institute of Technology Guwahati, Gumahati 781039, India 2Department of Chemistry and Center for Cell & Genome Science, The University of Utah, Salt Lake City, UT 84112, USA 3Department of Chemical Biology and Applied Chemistry, School of Engineering, Nihon University, Koriyama, Fukushima 963-8642, Japan 4Department of Chemistry, Roy and Diana Vagelos Laboratories (IAST), University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104, USA