RNA aptamer evolution: two decades of SELEction

Abstract

Aptamers are small non-coding RNAs capable of recognizing, with high specificity and affinity, a wide variety of molecules in a manner that resembles antibodies. This class of nucleic acids is the resulting product of applying a well-established screening method known as SELEX. First developed in 1990, the SELEX process has become a powerful tool to select structured oligonucleotides for the recognition of targets, starting with small molecules, going through protein complexes until whole cells. SELEX has also evolved along with new technologies positioning itself as an alternative in the design of a new class of therapeutic agents in modern molecular medicine. This review is an historical follow-up of SELEX method over the two decades since its first appearance.

Keywords: SELEX; aptamers; in vitro evolution; in vitro selection; non-coding RNAs.

Figure 1

SELEX evolution. This scheme shows the basic steps of SELEX (a) and the main modifications done over two decades (b). The methods indicated on (b) are positioned on each aspect of SELEX where modifications were proposed. The techniques on the center of (b) represent major changes—at least in three aspects—of classic SELEX. A: Library design, B: Target type, C: Partition and D: Elution and amplification.