Where are aptamers found?

Aptamers (from the Latin aptus – fit, and Greek meros – part) are oligonucleotide or peptide molecules that bind to a specific target molecule. Aptamers are usually created by selecting them from a large random sequence pool, but natural aptamers also exist in riboswitches.

What is the purpose of SELEX?

Systematic evolution of ligands by exponential enrichment (SELEX), also referred to as in vitro selection or in vitro evolution, is a combinatorial chemistry technique in molecular biology for producing oligonucleotides of either single-stranded DNA or RNA that specifically bind to a target ligand or ligands.

Are aptamers natural?

Aptamers are nucleic acid molecules that mimic antibodies by folding into complex 3D shapes that bind to specific targets. Although some aptamers exist naturally as the ligand-binding elements of riboswitches, most are generated in vitro and can be tailored for a specific target.

Where are aptamers used?

Like monoclonal antibodies, aptamers can be used for the molecular recognition of their respective targets. Aptamers have been successfully used for pathogen recognition, cancer recognition, monitoring environmental contamination, and as stem cell markers.

How are aptamers selected?

Aptamers can be obtained through an iterative selection process known as SELEX (systematic evolution of ligands by exponential enrichment) by using single-stranded DNA or RNA. An initial pool of 1014-1015 random oligonucleotide (ONT) strands are subjected to binding with the target.

Where do aptamers come from?

Aptamer is an artificial chemical antibody that is generated from the randomized nucleic acid library by three simple steps: binding, separation, and amplification. The selected aptamer has a high binding affinity with the target molecule. In most cases, aptamer was found to be better than antibodies.

How is SELEX done?

Specifically, SELEX process includes (1) the incubation of target molecules with the random sequence pools, (2) and the subsequent separation of unbound oligonucleotides and the elution of bound oligonucleotides, (3) then PCR amplification of bound aptamers.

What is the SELEX process?

SELEX is an iterative process in which highly diverse synthetic nucleic acid libraries are selected over many rounds to finally identify aptamers with desired properties. However, little is understood as how binders are enriched during the selection course.

Are aptamers synthetic?

Aptamers (synthetic antibodies) are (stable) single-stranded DNA, RNA, or peptide molecules capable of binding to its target antigen with high affinity and specificity. Aptamers (synthetic antibodies) have been developed against a wide variety of targets ranging from small organics to large proteins.

How are aptamers designed?

Aptamers are nucleic acid analogues of antibodies with high affinity to different targets, such as cells, viruses, proteins, inorganic materials, and coenzymes. Empirical approaches allow the design of in vitro aptamers that bind particularly to a target molecule with high affinity and selectivity.