Solid phase synthesis of 5′-diphosphorylated oligoribonucleotides and their conversion to capped m7 Gppp-oligoribonucleotides for uase as primers for influenza A virus RNA polymerase in vitro

We have synthesized four different 5′-diphosphorylated oligoribonucleotides, varying in length from 11 to 13 nucleotides by a new solid phase method. After deprotectlon and partial purification the 5′-diphosphorylated oligoribonucleotides could be converted to capped (m7Gppp)-oligoribonucleotides using guanylyl transferase. Radlolabelled capped oligoribonucleotides acted as primers for the influenza A virus RNA polymerase in vitro. The solid phase method described here should also allow the addition of 5′-diphosphates to synthetic ollgodeoxyribonucleotides and be capable of automation.