Chemical Synthesis, Analysis, and Purification of Ribozymes

The chemical synthesis of RNA, like DNA, is carried out in the 3′ to 5′ direction to take advantage of the high chemical reactivity of the 5′-hydroxyl group. Solid-phase chemistry currently provides the most effective means for the scale-up of RNA synthesis. The biological activity of chemically synthesized RNA (1 –3 ), equivalent to that of RNA derived by transcription methods (4 –6 ), is contingent on efficient synthesis and purification protocols. Chemical synthesis also allows for site-specific modifications, such as deoxynucleotides, phosphorothioates and modified nucleotides (7 –11 ).