RNA design by in vitro RNA recombination and synthesis.

The techniques of in vitro RNA synthesis and recombination are presented. These include the site-specific cleavage of RNA, the manipulation of terminal phosphates, and the ligation of RNA fragments. Areas of promising future research include the establishment of RNA cloning vectors and the use of in vitro transcription of natural or designed RNA genes. The chemical synthesis approach now offers the possibility of making large amounts of biologically active length RNAs and of incorporating modified or reporter nucleotides into RNA sequences for physical studies. The new RNA techniques taken with DNA technology will permit a new approach towards understanding the complexity of RNA metabolism and the relationship of structure to function in RNAs.