Introduction Aptamers are single-stranded oligonucleotides that fold into unique 3D structures to bind targets with high specificity. Often called “chemical antibodies,” they offer advantages over traditional protein binders. These molecules are discovered through SELEX (Systematic Evolution of Ligands by Exponential Enrichment), an iterative in vitro process that isolates high-affinity ligands from massive random libraries. The …
OX40 (CD134), a key costimulatory molecule in the tumor necrosis factor receptor superfamily, is crucial for enhancing T cell function and driving anti-tumor immunity, making it a significant focus in cancer immunotherapy research. Structure and Costimulatory Mechanism (i) Expression Pattern OX40 is a transmembrane glycoprotein expressed on activated T cells (peaking 48-72 hours post-activation), but …
SELEX Technology: Expert Guide to Choosing Between RNA and DNA Aptamers Overview of SELEX Technology Systematic Evolution of Ligands by EXponential enrichment (SELEX) is the gold-standard in vitro process for screening nucleic acid aptamers. This technology operates by cycling through “incubation-separation-amplification” steps to isolate high-affinity sequences from massive libraries (10¹³–10¹⁵ variants). While SELEX offers superior …