Universal solid supports for the synthesis of oligonucleotides with terminal 3'-phosphates

The preparation of two types of supports based on controlled pore glass (CPG) is presented. These supports are compatible with established phosphoroamidite chemistry of oligonucleotides synthesis giving rise to an oligonucleotide with terminal 3'-phosphate function during final deprotection. CPG was modified with: (i) methacrylic acid derivatives and 2-mercaptoethanol (1) or (ii) aminoalkylsilane, succinic anhydride and benzidine (2). Support 2 can be also used for the synthesis of partially protected oligonucleotide 3'-phosphates.