Diverse base-modified nucleotides have been synthesized and used as substrates for polymerase synthesis of modified nucleic acids.
The modifications include environment-sensitive fluorophores for imaging of DNA synthesis if live cells or sensing DNA-protein interactions, redox labels for electrochemical genosensors or redox coding of DNA bases, reactive groups for cross-linking with DNA- or RNA-binding proteins or masked epigenetic modifications for regulation of transcription. Synthesis of hypermodified nucleic acids containing up to four different modifications has been developed and used in selection of functional nucleic acids, i.e. aptamers.
