Profile: Sierra Bioresearch supplies a wide variety of analog nucleotides for anti-cancer/anti-viral research. We offer custom synthesis of mono di & triphosphates of many modified (analog) nucleosides based on purine & pyrimidine ribosides, arabino nucleosides, carbocyclic nucleosides and acyclic nucleosides. We offer modifications of the adenine, thymine, guanine, cytosine, uracil, adenosine, guanosine, thymidine, cytidine and uridine bases. We also offer various types of modifications for our custom synthesized analog nucleoside mono, di & triphosphates that include acyclo, alkyl, amino, arabino, aza, azido, azole, borano, carbocyclic, chloro, deaza, diamino, dideoxy, dihydro, fluoro, hydroxy, indole, iodo, iso, lyxo, mercapto, methoxy, methyl, nitro, oxo, propynyl, pseudo, pyrrole, thio plus many other modifications.