What is an Aptamer? Aptamers are single-stranded DNA or RNA oligonucleotides that fold into specific 3D shapes, enabling them to bind to target molecules (proteins, small molecules, cells, viruses) with high affinity and specificity, similar to antibodies. They are often called "chemical antibodies." Why Use Aptamer Screening Services in Drug Discovery? Efficiency: Outsourcing to experts with specialized platforms (SELEX) accelerates discovery. Cost-Effectiveness: Avoids capital investment in complex SELEX and NGS infrastructure. Expertise: Leverages specialized knowledge in oligonucleotide chemistry, bioinformatics, and target biology. Focus: Allows internal teams to concentrate on downstream therapeutic development. Core Components of an Aptamer Screening Service A full-service provider typically offers an end-to-end pipeline: 1. Project Design & Target Preparation Consultation: Defining the target (recombinant protein, cell surface marker, whole cell), desired affinity (nM-pM), and specificity (e.g., against homologs). Counter-SELEX Strategy: Planning to eliminate binders to non-desired epitopes or related targets to ensure high specificity. 2. In Vitro Selection (SELEX) The core technology is SELEX (Systematic Evolution of Ligands by EXponential enrichment). Advanced variants are used for complex targets: Protein-SELEX: For purified recombinant proteins. Cell-SELEX: For membrane proteins in their native conformation on live cells; identifies aptamers for diseased vs. healthy cells. Tissue-SELEX: For even more complex biological environments. Capture-SELEX: For small molecules that are difficult to immobilize. High-Throughput SELEX (HT-SELEX): Uses NGS early…
