Core Concept: SELEX SELEX (Systematic Evolution of Ligands by Exponential Enrichment) is an iterative process to select high-affinity, specific nucleic acid aptamers (ssDNA or RNA) against a target molecule. The magnetic bead-based method revolutionizes this by using beads as a solid, easily separable support, drastically improving speed and efficiency. How Magnetic Bead-Based SELEX Works (The Process) A professional service provider will execute this cyclic process, usually over 8-15 rounds: Key Advantages of the Magnetic Bead Method (Why it's the service of choice) Rapid Separation: Magnetic stands enable quick washing and buffer exchange, shortening each selection round from hours to minutes. Reduced Non-Specific Binding: Efficient washing minimizes background, leading to cleaner selection. Automation-Friendly: Perfectly suited for robotic liquid handlers, enabling high-throughput, reproducible selections. Flexibility with Targets: Immobilized Targets: Proteins, small molecules, cells, or viruses can be directly conjugated to the beads. Counter-Selection: Beads coated with non-target molecules (e.g., a related protein, cell type) can be used to subtract non-specific binders, dramatically enhancing specificity. What a Full-Service Provider Typically Offers 1. Project Design & Consultation Target characterization and strategy (native vs. tagged protein, cell surface marker). Selection of library type (DNA, RNA, modified nucleotides like 2'-F for stability). Design of counter-selection steps. 2. The SELEX Selection Process Library Synthesis: Starting with…
Core Components of a Small Molecule Target Service A comprehensive service follows the early drug discovery workflow: 1. Target Identification & Prioritization Bioinformatics & Omics Analysis: Mining genomic, proteomic, and clinical data to find proteins or pathways dysregulated in a disease. Genetic Screens: Using CRISPR-Cas9 or RNAi to knock out/knock down genes and identify which are essential for disease cell survival. Literature & Database Mining: Systematic review of existing scientific and patent data to propose novel or repurposable targets. 2. Target Validation In Vitro Models: Confirming the target's role in disease using engineered cell lines (overexpression, knockout) and relevant disease models (e.g., cancer cell lines, neuronal cultures). In Vivo Models: Using animal models (e.g., zebrafish, mice) to see if modulating the target (genetically or with a tool compound) has the desired therapeutic effect and is safe. Biochemical Validation: Demonstrating the target protein is expressed, has the expected activity, and is "druggable" (has a pocket where a small molecule can bind). 3. Assay Development & Screening This is a critical service. Providers develop robust tests ("assays") to measure target activity. Types of Assays: Biochemical Assays: Test compound binding/interaction with the purified target protein (e.g., enzymatic activity, protein-protein interaction). Cell-Based Assays: Test compound function in a living cell (e.g., reporter…
