Core Value: From a "Black Box" to a "Data Dashboard" A traditional SELEX service infers progress indirectly (e.g., via qPCR binding assays). An HTS-SELEX service provides a molecular-level census of the entire evolving library, offering: Quantitative Tracking: Exact counts and frequency changes for every sequence across rounds. Early Identification: High-affinity aptamer families can be spotted and validated mid-process, often shortening the project. Informed Decision-Making: Data guides adjustments in stringency, timing of counter-selection, and when to stop the selection. Typical Service Workflow & Data Integration A sophisticated HTS-SELEX service integrates sequencing as follows: Sequencing from the Start: The naive starting library is sequenced to establish baseline diversity. Sequencing at Every Critical Point: Key rounds (e.g., Rounds 3, 5, 7, 9, final) are sequenced, including sometimes the "bound" vs. "unbound" fractions from a single round for comparative analysis. Real-Time Bioinformatics Pipeline: Enrichment Analysis: Calculates the fold-enrichment of every sequence or sequence family across consecutive rounds. Cluster Analysis: Groups sequences into families based on homology, revealing convergent evolution. Motif & Structure Prediction: Identifies conserved primary sequence motifs and consensus secondary structures among enriched families. Informed Selection Steering: Based on the data, the service provider may: Adjust Stringency: Increase selection pressure if enrichment is too slow, or decrease it if diversity is collapsing too fast. Introduce Negative Selection: Add a counter-SELEX round if promiscuous…
CUSTOM APTAMER DISCOVERY & DEVELOPMENT is the process of creating target-specific single-stranded DNA or RNA aptamers—short nucleic acids that fold into 3D shapes capable of binding proteins, small molecules, cells, vesicles, or other targets with antibody-like selectivity. Most custom programs rely on SELEX (Systematic Evolution of Ligands by EXponential enrichment), then refine “hits” into robust, application-ready binders through sequencing-driven analysis and post-selection optimization. 1) What Aptamers Are (and Why They’re Used) Aptamers are typically ~15–90 nucleotides long and can be engineered to bind targets across a wide size range (from small molecules to whole cells). They’re attractive because they are chemically synthesized (batch-to-batch consistency), can be readily labeled (fluorophores, biotin, etc.), and are generally thermally stable and re-foldable—features that often simplify assay development and manufacturing. Common aptamer use cases Diagnostics & biosensors (capture probes, signal transducers, point-of-care formats) Targeted delivery & therapeutics research (cell-directed binding, payload delivery concepts) Affinity purification & analytical workflows (pull-downs, enrichment, separations) 2) The Core Workflow in Custom Aptamer Discovery A custom program is best thought of as a pipeline with four linked decisions: target format → selection strategy → analytics → optimization. Step A — Target Definition and “Bindability” Planning…
