Aptamers have gained recognition for their ability to bind to a wide range of targets with high affinity and specificity which makes them an exciting tool for scientific research, clinical diagnostics, and potential therapeutic applications. These short DNA or RNA single-stranded molecules with unique structures, and offer several advantages over traditional antibodies, including lower immunogenicity, molecular weight, and synthesis cost.
To select aptamers, the systematic evolution of ligands by the exponential enrichment (SELEX, Figure 1) method is commonly employed. SELEX involves several stages, with the first step being the exposure of a single-stranded DNA aptamer library to the target molecule. Following the binding, unbound oligonucleotides are washed away, and the DNA fragments bound to the target are amplified through PCR. This process is repeated for multiple selection rounds to enrich the aptamer pool with sequences exhibiting high specificity and affinity for the target.