What are Peptide Screening Services? These are specialized contract research services offered by biotech companies and CROs (Contract Research Organizations) to discover, optimize, or validate peptide-based molecules for various applications. They provide the expertise, libraries, and high-throughput technologies to efficiently identify peptide hits from vast molecular collections. Core Types of Peptide Screening Services 1. Library-Based Screening This is the most common starting point for discovery. Synthetic Peptide Libraries: Collections of thousands to millions of chemically synthesized peptides. Positional Scanning Libraries: For epitope mapping or identifying key amino acid residues. Truncation & Alanine Scanning: To find the minimal active sequence and critical residues. Phage Display Libraries: The largest and most diverse format (up to 10^11 unique sequences). A library of bacteriophages, each displaying a unique peptide on its coat protein, is panned against a target (e.g., a protein, cell). mRNA/Ribosome Display Libraries: Cell-free systems that link the peptide to its encoding mRNA, allowing for even larger libraries and easier mutagenesis. 2. Functional & Application-Specific Screening Services are tailored to the desired peptide function: Target-Based Screening: Against purified proteins (e.g., enzymes, receptors, GPCRs, protein-protein interaction interfaces). Cell-Based Screening: For peptides that modulate cell signaling, internalize into cells (CPPs), or have antimicrobial (AMP) or anticancer activity. Antigen/Antibody Screening: For epitope mapping, vaccine development,…
Aptamers are short single-stranded DNA or RNA molecules that fold into 3D structures capable of binding targets (proteins, small molecules, cells, or even complex particles) with high specificity and affinity. “Aptamer methods” usually refers to the full pipeline: library design → selection (SELEX) → enrichment monitoring → sequencing & bioinformatics → candidate optimization → biophysical/functional validation → stability engineering. Modern platforms improve speed and hit quality by combining smarter selection pressures with microfluidics and next-generation sequencing. 1) Core Aptamer Selection Method: SELEX (Systematic Evolution of Ligands by EXponential Enrichment) 1.1 Classical SELEX workflow (baseline method) Start with a random oligonucleotide library (often 10^13–10^15 unique sequences) Incubate library with the target Partition bound vs unbound sequences Elute binders Amplify (PCR for DNA; RT-PCR + transcription for RNA) Repeat iterative rounds with increasing stringency until enrichment is achieved Why it works: each round increases the fraction of sequences that can bind under the imposed conditions (buffer, temperature, competitor molecules, etc.). Why it’s hard: classical SELEX can be slow, labor intensive, and prone to amplification bias—hence the rise of “advanced SELEX” platforms. 1.2 “Stringency engineering” (how you make aptamers useful) Selection success often depends less on the target itself…
Aptamers are short, single-stranded DNA or RNA sequences that fold into 3D shapes capable of binding specific targets—proteins, small molecules, ions, cells, or even complex mixtures—with high affinity and selectivity. Because they are chemically synthesized, readily modified, and often less immunogenic than protein binders, aptamers have matured into a versatile “molecular toolkit” used across diagnostics, biosensing, therapeutics, imaging, and bioprocessing. This article explains APTAMER APPLICATIONS from fundamentals to advanced use-cases, with an emphasis on how teams translate an aptamer sequence into a functioning assay, sensor, drug carrier, or imaging probe. 1) How Aptamers Are Created (Why Selection Method Shapes Applications) Most aptamers are discovered through SELEX (Systematic Evolution of Ligands by EXponential enrichment): iterative rounds of binding, separation, and amplification that enrich sequences best suited to a chosen target and conditions. Modern SELEX variants—such as cell-SELEX, microfluidic SELEX, and capillary electrophoresis SELEX—aim to shorten selection time, improve specificity, and better match real-world sample environments. The practical result is that application performance often depends as much on selection constraints (buffer, temperature, counter-selection targets, matrix effects) as on the final nucleotide sequence. Key takeaway: If the intended application involves serum, saliva, food extracts, or environmental water, designing SELEX conditions to…
Custom Cell Culture Services are specialized, on-demand laboratory offerings where an external team cultures cells to your requirements—cell type, format, scale, timing, and quality attributes—so you can generate reliable biological material or assay-ready cells without building the full in-house infrastructure. These services commonly support mammalian and microbial culture work for applications like protein expression, assay development, drug screening, and functional studies, often extending into optimization, scale-up, and quality control testing. What “Custom” Really Means in Cell Culture In practice, “custom” usually refers to tailoring inputs, process conditions, and outputs: Inputs: your chosen cell line (or a requested cell type), media requirements, supplements, antibiotics policy, culture vessels, and documentation needs. Some providers also isolate primary cells on request, depending on scope and compliance. Process conditions: seeding density, passage number targets, feeding schedule, incubation parameters, adaptation steps, and any special handling for fragile or slow-growing cells. Outputs: frozen vials, live plates/flasks, pellets/lysates, supernatants, or assay-ready formats with defined viability and confluence ranges. A good mental model: you’re not “buying cells,” you’re purchasing a controlled biological manufacturing workflow with agreed acceptance criteria. Common Deliverables and Use Cases Custom cell culture is often used to produce consistent starting material…
“CATALOG APTAMERS & REAGENTS” usually refers to ready-to-order, pre-characterized aptamer affinity binders and the supporting assay reagents that make those binders usable in real experiments (e.g., labeling, immobilization, buffers, and controls). Aptamers themselves are short, single-stranded DNA or RNA (or related chemistries) selected from very large libraries to bind a specific target with high affinity and specificity—often described as antibody-like binding, but built from nucleic acids and produced by chemical synthesis. 1) What Are Aptamers (and Why They Matter as Reagents)? Aptamers are single-stranded nucleic acids that fold into 3D structures capable of recognizing targets such as proteins, small molecules, ions, or even cells. They are typically discovered through SELEX (Systematic Evolution of Ligands by EXponential enrichment), an iterative selection process that enriches sequences that bind the desired target. What makes aptamers especially “catalog-friendly” is that once a sequence is known, it can be reliably reproduced by chemical synthesis, and easily chemically modified (for example, adding a fluorophore or biotin) to fit common assay formats. 2) “Catalog Aptamers” vs Custom Aptamer Discovery Catalog Aptamers (ready-to-order) Catalog aptamers are fixed, known sequences that have been previously selected and are sold as standard products. Their main value…
Aptamers are short single-stranded DNA or RNA molecules that fold into 3D shapes capable of binding specific targets (proteins, small molecules, cells) with high affinity and selectivity. The classic way to discover them is SELEX(Systematic Evolution of Ligands by EXponential enrichment): iterative rounds of binding, partitioning, amplification, and re-selection. What changed the field is high-throughput sequencing (HT-SELEX)—sequencing pools after each round—turning SELEX into a data-rich optimization problem where bioinformatics is no longer optional but central to identifying true binders, understanding enrichment dynamics, and avoiding artifacts. This article explains how bioinformatics for aptamer selection works end-to-end, what signals to extract from sequencing data, how to connect sequence to structure and function, and where modern machine learning fits—without relying on external case studies or outbound links. 1) Why Bioinformatics Matters in Aptamer Selection Traditional SELEX often ends with testing a handful of sequences from late rounds. HT-SELEX changes the game by giving you: Population-level visibility: you can track millions of sequences across rounds, not just a few clones. Early discovery: promising families can emerge before the pool looks “clean,” enabling earlier decision-making and fewer wet-lab rounds when combined with modeling. Artifact detection: PCR bias, sequencing errors, and “sticky” motifs can…
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…
“Completion of SELEX” refers to the point in the Systematic Evolution of Ligands by EXponential enrichment (SELEX)workflow where iterative selection rounds have produced an enriched nucleic-acid pool (DNA or RNA) that contains high-affinity, high-specificity binding sequences (aptamers) for a defined target, and further rounds provide diminishing improvements. In practical terms, completion is less a single universal round number and more a decision point supported by enrichment evidence, performance metrics, and downstream readiness. 1) SELEX in One Picture (Why “Completion” Exists at All) SELEX is an iterative evolutionary loop performed in vitro: Start with a diverse library (randomized nucleic-acid sequences). Bind the library to a target (protein, small molecule, cell surface, complex mixture, etc.). Partition: separate binders from non-binders (the critical “selection” step). Elute and amplify the binders (PCR for DNA; RT-PCR for RNA). Repeat with increasing stringency (less target, harsher washes, counter-selection, etc.). “Completion” matters because every additional round costs time, introduces amplification bias, and can over-enrich “fast amplifiers” rather than “best binders.” Modern practice treats completion as an optimization endpoint, not a ritual number of rounds. 2) What “Completion of SELEX” Typically Means (Conceptual Definition) A common knowledge-centered definition is: The pool has converged toward one…
What “SELEX Aptamer Selection” Means SELEX stands for Systematic Evolution of Ligands by Exponential Enrichment. In plain terms, SELEX aptamer selectionis an iterative laboratory workflow that starts with a huge pool of random DNA or RNA sequences and repeatedly enriches the fraction that binds a chosen target with high affinity and specificity. The “winners” are called aptamers—single-stranded nucleic acids that fold into 3D shapes capable of target recognition, often compared to “chemical antibodies,” but made by selection and synthesis rather than immune systems. Core Concept: Darwinian Evolution in a Test Tube SELEX is essentially variation + selection + amplification: Variation: Begin with a randomized oligonucleotide library (often ~10^13–10^16 unique sequences). Selection: Expose the library to the target; keep sequences that bind. Amplification: PCR (or RT-PCR for RNA workflows) amplifies binders to create the next-round pool. Increasing stringency: Each round tightens conditions (less target, harsher washes, more competitors), enriching the best binders over multiple cycles. Most conventional SELEX workflows run multiple rounds (often roughly 6–15) before candidates are sequenced and characterized. The Classic SELEX Workflow (Step-by-Step, With the “Why”) 1) Library design (the “starting universe”) A typical library contains: A random region (e.g., N30–N60) that can…
“Diagnostics and Therapeutics” is the paired engine of modern healthcare: diagnostics generate actionable evidence about what is happening in the body, and therapeutics use that evidence to choose (and adjust) interventions that improve outcomes. As medicine becomes more data-rich—through molecular testing, advanced imaging, and continuous monitoring—the relationship between diagnostics and therapeutics is shifting from a linear “test-then-treat” workflow to a dynamic feedback loop that refines decisions over time. 1) What “Diagnostics” Means (Beyond Simply Naming a Disease) In clinical practice, diagnostics refers to the tools and methods used to detect, characterize, and track disease-related signals. Importantly, diagnostics is not a single test—it’s a system of evidence that supports decisions across the entire care pathway: Screening diagnostics: detect risk or early disease signals before symptoms are obvious. Diagnostic confirmation: distinguish between conditions with similar presentations. Prognostic diagnostics: estimate likely disease course and severity. Predictive diagnostics: forecast whether a patient is likely to benefit from a specific therapy (a key concept in precision medicine). Monitoring diagnostics: measure response, relapse, or adverse effects over time, enabling treatment adjustment. Major diagnostic categories used today Clinical laboratory diagnostics (blood, urine, tissue, etc.) and medical imaging are foundational, but the fastest-growing…
