We understand that in the fields of precision medicine, diagnostic development, and drug discovery, researchers need targeting and recognition tools that go beyond traditional antibodies, offering greater programmability and stability. KMD Bioscience provides professional, efficient, and customized one-stop aptamer development services based on mature platform technologies. We are committed to helping you obtain "chemical antibodies" with high affinity and specificity for your target through advanced screening technologies, accelerating your research and translation processes. Service Core: From Random Library to High-Affinity Aptamers Aptamers are a class of single-stranded oligonucleotides (DNA or RNA) that can specifically bind to targets. Their three-dimensional structures can recognize a wide range of targets, including proteins, small molecules, cells, and even microorganisms. Hence, they are hailed as "chemical antibodies." Compared to antibodies, aptamers offer unique advantages such as chemical synthesis, batch-to-batch consistency, ease of modification, and a broad target range. The core of our service is based on SELEX (Systematic Evolution of Ligands by Exponential Enrichment) technology. Through in vitro screening, we enrich and identify the aptamer sequences with the strongest binding affinity for your target molecule from vast random sequence libraries. Our Technology Platform: Matching the Optimal Solution for Different Targets To meet diverse research needs, we have established…
KMD Bioscience: Professional Aptamer Development Services Company Profile: An Innovation-Driven Biotechnology Partner KMD Bioscience Co., Ltd. (Tianjin) is a National High-Tech Enterprise dedicated to becoming a leading provider of drug discovery and related support services. With cutting-edge technology R&D at our core, we offer high-quality, one-stop CRO (Contract Research Organization) services to scientists, research institutions, pharmaceutical and biotech companies worldwide, aiming to advance the development and innovation of medical technology. Our foundation is built on solid quality and technology: we are a National Patent Pilot Unit, hold ISO9001:2015 Quality Management System Certification for our laboratories, and possess over 30 patents and 4 registered trademarks. Our technical team is highly skilled, with over 90% of R&D personnel holding a Master's degree or higher, ensuring expert support for every project. Each year, we successfully deliver nearly a thousand technical service projects to global clients, covering protocol design, project consultation, and execution. Leveraging our five core platforms—Antibody Drug Discovery, Antibody Engineering, Protein Expression & Purification, and Stable Cell Line Development—we combine deep antibody engineering expertise with advanced molecular biology technologies to formally introduce our professional Aptamer Development Service, providing clients with novel tools for research and application. Service Overview: A Full-Spectrum Aptamer Solution from Screening to Application A nucleic acid aptamer (Aptamer)…
Small molecules are some of the most valuable—and most difficult—targets in molecular recognition. They include metabolites, drugs, toxins, cofactors, and signaling compounds that often weigh only a few hundred Daltons. Developing expertise in aptamers to small molecules means mastering a set of selection and validation strategies that differ substantially from protein-target aptamer work, because small molecules offer fewer contact points, weaker “handles” for separation, and more ways to generate false positives. This article explains how small-molecule aptamers are discovered, why selection is uniquely challenging, how advanced SELEX variants improve success rates, and what “good” looks like when you engineer an aptamer into a sensor, assay, or therapeutic concept. 1) What makes small-molecule aptamers special? Aptamers are single-stranded DNA or RNA sequences that fold into 3D shapes able to bind a target through non-covalent interactions—hydrogen bonding, π–π stacking, electrostatics, and shape complementarity. For proteins, large surfaces provide many contacts, so binding can be robust even when the selection workflow is imperfect. Small molecules are different: Tiny binding interface: fewer interaction opportunities means affinity can be harder to evolve and easier to mis-measure. Separation is tricky: in classic SELEX you often immobilize the target; immobilization can change the target’s presentation…
“PARTNERING WITH BASE PAIR” can read like a collaboration phrase, but in life-science contexts it also naturally points readers toward the core concept of base pairing—how nucleic-acid “bases” recognize each other to store, copy, and interpret genetic information. This article treats the keyword as an educational doorway: first, what “base pair partnering” means chemically; then how canonical and non-canonical pairing shapes biology, biotechnology, and molecular design. 1) What is a “base pair,” and what does “partnering” mean? A base pair is two nucleobases (the “letters” of DNA/RNA) that associate primarily through hydrogen bonding and complementary shape/chemistry. In the classic (canonical) picture: In DNA, A pairs with T (two hydrogen bonds) and G pairs with C (three hydrogen bonds). In RNA, U replaces T, so A pairs with U, while G still pairs with C. So “partnering” here means: which base preferentially pairs with which, and under what structural rules. 2) Canonical pairing: the rule set that enables reliable genetic copying Canonical Watson–Crick pairing is the backbone of genetic stability. Its reliability comes from: Complementary hydrogen-bond donors/acceptors lining up. Geometric consistency that supports the uniform double-helix shape. Stacking interactions (bases stacking like coins) that add stability beyond hydrogen…
If you’ve ever wondered “WHY BASE PAIR?”, the short answer is: base pairing is the molecular rulebook that makes genetic information readable, copyable, and reliable. Base pairs are not just a detail of DNA structure—they’re the mechanism that lets cells store information, duplicate it with high accuracy, and use it to build functional molecules. What Is a Base Pair? A base pair is a pair of nucleobases that bind together in double-stranded nucleic acids (DNA, and many structured regions of RNA) through hydrogen bonding and geometric fit. In canonical (most common) pairing: DNA: Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C) RNA: Adenine (A) pairs with Uracil (U), and Guanine (G) pairs with Cytosine (C) This is often called Watson–Crick base pairing, and it’s the foundation of the DNA double helix’s consistent shape and information redundancy. Why Base Pairing Exists: The “Two-Copy” Advantage Base pairing creates complementarity: each strand “predicts” the other. That matters because: Information redundancy With two complementary strands, genetic information is effectively stored twice. If one strand is damaged, cells can often restore the correct sequence using the other as a template. (This concept underpins multiple DNA repair pathways,…
Aptamers—short, single-stranded DNA or RNA oligonucleotides that fold into target-binding structures—are attractive tools for therapeutics, diagnostics, and biosensing. But one limitation shows up again and again in real-world use: stability. In biological fluids, aptamers can be degraded by nucleases, lose their functional conformation, or get cleared rapidly due to small size. “Enhancing aptamer stability” therefore means engineering aptamers to retain integrity and function under the conditions they must actually operate in—serum, cells, elevated temperatures, long storage, or repeated assay cycles. This article explains the major stability failure modes and the best-established enhancement strategies—organized the way practitioners typically make design decisions. 1) What “Aptamer Stability” Really Means (It’s Not One Thing) When people say “aptamer stability,” they often blend multiple properties: Nuclease stability (biostability): resistance to DNases/RNases in serum, plasma, and tissues. Structural/conformational stability: ability to keep the correct fold that binds the target (especially under ionic changes, crowding, or temperature shifts). Thermal stability: higher melting temperature (Tₘ) and robust folding across a wider temperature range. Circulation stability (pharmacokinetic stability): staying in the bloodstream long enough to matter—often limited by renal filtration for small oligos. Functional stability: maintaining binding affinity/specificity after modifications, storage, repeated use, or immobilization. A…
Negative aptamer selection—often called negative selection or counter-selection—is a deliberate filtering step in SELEX(Systematic Evolution of Ligands by EXponential enrichment) designed to remove sequences that bind to the wrong things. Instead of enriching binders to your intended target, negative selection enriches your final pool for what you actually want in real-world use: high specificity, low background, and minimal cross-reactivity. In modern aptamer discovery, negative selection is not “optional polish.” It is one of the most effective ways to prevent selection artifacts—like aptamers that bind to beads, linkers, tags, surfaces, common matrix components, or closely related off-target molecules—from dominating your pool. 1) What “Negative Aptamer Selection” Means (and Why It Exists) During SELEX, you start with a huge randomized DNA/RNA library and iteratively enrich sequences that bind. The catch is that many sequences bind strongly to unintended components in the experimental system: immobilization substrates (e.g., beads, membranes) affinity tags or capture molecules (e.g., streptavidin–biotin systems) blockers, serum proteins, plastic, or assay buffers structurally similar molecules (analogs) that you must not bind Negative selection introduces a decoy binding step: you expose the library to an unwanted target (or “negative target”), then discard the sequences that bind it and keep…
Aptamers are short, single-stranded nucleic acids—typically ~20–100 nucleotides—that fold into defined 3D shapes and bind targets (proteins, small molecules, ions, cells) with high affinity and specificity. They are often described as “chemical antibodies,” but they behave differently: their binding comes from nucleic-acid folding + surface complementarity, and their performance is tightly linked to sequence chemistry, structure, and degradation pathways. When your core question is “DNA aptamers or RNA aptamers?”, the best answer is not a slogan. It’s a decision based on (1) structural needs, (2) stability environment, (3) manufacturability, (4) modification strategy, and (5) application constraints. 1) The Fundamental Difference: Structural Vocabulary vs Environmental Toughness RNA aptamers: richer folding vocabulary RNA has a 2′-OH group on the ribose, which expands hydrogen-bonding possibilities and supports a larger “structural vocabulary” (hairpins, internal loops, bulges, pseudoknots, complex tertiary contacts). In practice, this often means more diverse and intricate 3D conformations, which can translate into excellent binding performance for some targets. Takeaway: Choose RNA when the target demands highly nuanced shape recognition (e.g., challenging protein surfaces or structured RNA targets). DNA aptamers: generally more chemically stable and simpler DNA lacks the 2′-OH group and is typically more resistant to base-catalyzed…
Aptamers and antibodies are both molecular recognition tools—they bind targets with high specificity and affinity—but they come from very different histories. Antibodies emerged from immunology and serum therapy, while aptamers grew out of in vitro evolution and nucleic-acid chemistry. Understanding their origins helps explain why they behave differently in diagnostics, research, and therapeutics. 1) What Antibodies Are—and Why Their History Matters Antibodies are proteins produced by the immune system that recognize antigens. Their “history” is tightly linked to the birth of modern immunology: early observations that blood serum could protect against infection eventually led to the concept of specific “anti-bodies” as functional components of immunity. Over the 20th century, progress in structural biology and molecular genetics clarified how antibodies achieve both diversity and specificity, culminating in technologies that made antibodies reliable lab and industrial tools. Key turning point: monoclonal antibodies A major leap occurred in the 1970s with the development of methods to produce monoclonal antibodies—antibodies of single, defined specificity that could be generated reproducibly and at scale. This transformed antibodies from biological curiosities into standardized reagents for diagnostics and targeted therapy. 2) What Aptamers Are—and How They Were Discovered Aptamers are short, single-stranded nucleic…
CELL-SELEX (Cell-Based Systematic Evolution of Ligands by EXponential enrichment) is a selection strategy used to discover nucleic-acid aptamers—short single-stranded DNA or RNA molecules that fold into shapes capable of binding cellular targets with high affinity and specificity. What makes CELL-SELEX AND BIOMARKER DISCOVERY such a powerful pairing is that cell-SELEX can enrich binders against native cell-surface features (often membrane proteins, glycoproteins, lipids, or complex epitopes) without needing to know the target in advance. This is especially valuable in biomarker discovery, where the “best” marker may be unknown, heterogeneous, or highly dependent on the cellular context. 1) What CELL-SELEX Is (and Why It Matters for Biomarkers) Traditional SELEX often starts with a purified target (e.g., a recombinant protein). In cell-SELEX, the “target” is a living cell population that represents a phenotype you care about—such as a disease subtype, drug-resistant cells, activated immune cells, or a specific differentiation stage. The selection process enriches aptamers that bind those cells while removing sequences that bind irrelevant or shared features. Why this matters for biomarkers: Native conformation is preserved. Cell-surface proteins keep their natural folding, post-translational modifications, and membrane context—features that can be lost in purified preparations. Unbiased discovery. You can discover binding…
