Chemical nucleic acid synthesis, modification and labelling.

The chemical synthesis of RNA on solid phase has now become routine using labile protecting groups and mild deprotection methods. The great interest in antisense technology has sparked the development of P-chiral phosphorothioates and a large number of DNA analogues with modified sugars and/or backbones to increase resistance to nucleases, and with modifier groups attached to the sugar, nucleobase or internucleotide function to aid cellular uptake.