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,…
Think of it as a sophisticated, high-throughput search and test process. Instead of you building and running every experiment in your own lab, you outsource the initial heavy lifting to experts with specialized libraries and automated systems. Here’s a detailed breakdown: Core Concept The goal is to sift through vast collections (libraries) of peptides—short chains of amino acids—to find the few that bind to a specific target (like a protein, receptor, or cell), catalyze a reaction, or exhibit a desired function (e.g., antimicrobial activity). Key Components of Peptide Screening Services Peptide Libraries: Synthetic Libraries: Collections of thousands to millions of chemically synthesized peptides. They can be diverse (random sequences) or focused (based on a known protein family or structure). Phage Display / Yeast Display Libraries: Genetic libraries where each peptide is displayed on the surface of a virus (phage) or yeast cell, with its DNA sequence inside. This allows for easy amplification and sequencing of "hits." Screening Assays (The "How"): Binding Screens: The most common. Immobilize your target and see which peptides from the library stick to it. Techniques include ELISA, surface plasmon resonance (SPR), and biopanning (for phage display). Functional Screens: Test for a biological effect, like enzyme inhibition, antimicrobial killing, or cell penetration. High-Throughput Screening (HTS): Automated…
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…
“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…
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…
Aptamers are short, single-stranded nucleic acid molecules (DNA or RNA) that fold into specific 3D shapes and bind targets with high affinity and selectivity—often compared to how antibodies recognize antigens, but built from nucleic acids rather than proteins. Unlike a “generic DNA strand,” an aptamer’s function comes from structure: loops, stems, bulges, pseudoknots, and other motifs that create a binding surface matching a target’s geometry and chemistry. Targets can include proteins, peptides, small molecules, ions, and even whole cells (depending on the selection strategy). Why Aptamers Matter (and How They Differ From Antibodies) Aptamers are often described as “chemical antibodies,” but the differences are exactly why they’re valuable. Key advantages frequently highlighted Low immunogenicity (reduced risk of provoking immune responses) High stability and the ability to refold after denaturation in many cases Easy chemical synthesis (batch consistency, scalable manufacturing) Straightforward modification (labels, linkers, immobilization handles) Trade-offs you should know Nuclease sensitivity (especially RNA aptamers) can be a limitation in biological fluids unless stabilized. Selection bias can occur during discovery (e.g., PCR bias), meaning “best in the tube” isn’t always “best in reality.” Very high affinity does not automatically guarantee best real-world specificity; selection conditions matter. …
Peptides sit in a sweet spot between small molecules and biologics: they can be engineered for high specificity, tuned with chemical modifications, and explored rapidly through libraries. But peptide screening is not “just HTS with different molecules.” It blends chemistry (library design and synthesis), biology (assay selection and target context), and analytics (MS-based confirmation, binding kinetics, stability, and sometimes regulated bioanalysis). That is why many teams partner with a Contract Research Organization (CRO) for Peptide Screening—to industrialize the workflow from idea → hits → optimized leads, while keeping data quality, reproducibility, and documentation strong. Below is a knowledge-focused overview of what peptide-screening CROs typically do, the major screening technologies, the deliverables you should expect, and the technical “gotchas” that often decide whether a campaign succeeds. 1) What a “CRO for Peptide Screening” actually provides (beyond bench capacity) A peptide-screening CRO usually covers some combination of these pillars: Library strategy + synthesis execution Peptide discovery begins with what you choose to search. Many CROs help design libraries for the biological question (agonist vs antagonist, surface binder vs enzyme substrate, linear vs cyclic peptides, inclusion of non-natural amino acids, etc.), then manufacture the library and track identities and…
Expert Aptamer Analysis Services: From Screening to Validation with KMD Bioscience At KMD Bioscience, we specialize in unlocking the power of aptamers—single-stranded DNA or RNA molecules that bind to specific targets with high affinity and specificity. Our comprehensive Aptamer Analysis Services provide end-to-end solutions, guiding your project from initial discovery through rigorous characterization and validation. We empower researchers in therapeutics, diagnostics, and biotechnology with precise, reliable data to accelerate their development pipelines. Why Choose Aptamers? Often termed "chemical antibodies," aptamers offer unique advantages: reversible denaturation, chemical stability, low immunogenicity, and ease of chemical modification. Our services help you leverage these benefits by ensuring you select and characterize the most effective aptamer for your unique application. Our Core Aptamer Analysis Services 1. SELEX (Systematic Evolution of Ligands by Exponential Enrichment) Optimization & Monitoring The journey begins with robust selection. We don’t just perform SELEX; we optimize and monitor it for maximum success. Custom Library Design: Tailored oligonucleotide libraries based on your target’s nature (proteins, small molecules, cells). Process Monitoring: We use qPCR and high-throughput sequencing (HTS) at critical rounds to monitor enrichment, allowing for data-driven decisions to truncate or continue the selection process efficiently. Counter-Selection: Integration of counter-targets to eliminate non-specific binders and enhance specificity from…
Unlock High-Affinity Probes with Subtractive SELEX Services at KMD Bioscience At KMD Bioscience, we specialize in transforming the intricate science of molecular selection into powerful, practical solutions. Our Subtractive SELEX (Systematic Evolution of Ligands by EXponential Enrichment) Services are designed to isolate high-specificity, high-affinity aptamers—single-stranded DNA or RNA molecules—against your most challenging targets. In a landscape crowded with biological noise, our subtractive approach ensures you capture the precise molecular keys you need. What is Subtractive SELEX? Traditional SELEX is a powerful iterative process that selects aptamers from vast random-sequence libraries by binding to a target molecule. However, when the target is complex (like a specific cell type, a post-translationally modified protein, or a rare epitope on a common protein), background binding to similar or related structures can dominate, yielding non-specific aptamers. Subtractive SELEX introduces a critical purification step. Before or during selection against the desired target, the nucleic acid library is pre-incubated with non-target or counter-target structures (e.g., a non-target cell line, a non-modified protein, or a common protein domain). Sequences that bind to these undesired structures are actively removed or "subtracted." The remaining, pre-cleared library is then exposed to the true target of interest. This process dramatically enriches for aptamers that uniquely recognize…
Unlock Complex Targets with Our Advanced Toggle SELEX Services At KMD Bioscience, we push the boundaries of aptamer discovery. Traditional SELEX (Systematic Evolution of Ligands by EXponential enrichment) can face challenges with targets that are difficult to immobilize, have low solubility, or require recognition under specific physiological conditions. Our proprietary Toggle SELEX platform provides a powerful, flexible solution to overcome these hurdles and deliver high-affinity, high-specificity aptamers for your most demanding targets. What is Toggle SELEX? Toggle SELEX is an intelligent, counter-selection strategy that evolves aptamers through alternating selection pressures. Instead of selecting solely for binding to your target, the process dynamically toggles between: Positive Selection: Enriching nucleic acid libraries that bind to your primary target. Negative Selection (Counter-Selection): Actively removing sequences that cross-react with closely related molecules, non-target isoforms, or the immobilization matrix itself. This iterative "on/off" selection creates a powerful filtering mechanism, driving the evolution of aptamers with exceptional specificity and minimizing off-target binding. Our Toggle SELEX Advantage: Precision by Design We customize the toggle parameters to fit your exact needs, making it ideal for: Discriminating Between Highly Similar Targets: Isolate aptamers that distinguish between protein family members (e.g., kinase isoforms), mutant vs. wild-type proteins, or phosphorylated vs. non-phosphorylated states. Targeting Membrane Proteins & Complex Antigens: Use cell-based…
