What are aptamers?
Aptamer
Aptamers are short, single-stranded DNA or RNA molecules that fold into structures capable of binding specific targets, including proteins and small molecules. This page focuses on nucleic acid aptamers.
Aptamers can serve as recognition probes in diagnostics, biosensors and research. Binding affinity, specificity and stability must be evaluated under the intended sample, buffer, temperature and labeling conditions.
Aptamer·SELEX Frequently Asked Questions
Q1. What is SELEX?
This is a method to concentrate binding candidates by repeatedly performing target binding, separation, and amplification in a library containing many mixed nucleic acid sequences. After candidate discovery, the binding characteristics of individual sequences are evaluated separately.
Q2. Can aptamers always replace antibodies?
The choice depends on the purpose of application and the target. While it offers the advantage of being chemically synthesized and modified, stability in the sample environment and non-specific binding must be verified.
Q3. Can the discovered aptamers be used directly in diagnostic kits?
Diagnostic performance is not determined solely by candidate binding. Detection limits, cross-reactivity, and reproducibility are reviewed on actual specimens and platforms, and labeling and immobilization conditions are adjusted if necessary.
Q4. What is the approach of H-SELEX?
SB BIOSCIENCE introduces H-SELEX technology, which utilizes antibody-antigen complexes to search for aptamer candidates that do not overlap with antibody binding sites. Applicability and the scope of validation are confirmed through target-specific consultations.
Q5. What information is required for a quote request?
Please provide the target name, sample type, purpose of use, desired analysis conditions, and schedule. After discussing target preparation and the scope of candidate evaluation, we will provide the scope of work and an estimate.
Related Information
Aptamer Discovery Service: https://www.sbbioscience.com/services/aptamerselection
Introduction to H-SELEX Technology: https://www.sbbioscience.com/rnd/aptamer-selection-technology
References
Zhou J, Rossi J. Aptamers as targeted therapeutics: current potential and challenges. Nature Reviews Drug Discovery (2017). DOI: 10.1038/nrd.2016.199
https://www.nature.com/articles/nrd.2016.199
Antibodies
Aptamer
Binding mechanism
Target rangeToxicity
Size (kDa)
Manufacturing method
Recognition of antigen's three-dimensional structure and site
Various antigens, including proteins and small molecules
Immunogenicity evaluation by antibody type
IgG reference: approximately 150 kDa
Cell-based expression and purification
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Target recognition using three-dimensional structure
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Various targets including proteins and small molecules
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Safety assessment by sequence and modification is necessaryVaries by sequence
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Chemical synthesis and modification
Binding mechanism
Target rangeToxicit
Size (kDa)
Manufacturing method