Aptamer Screening through SELEX and Phage Display

Aptamers bind a specific target molecule, or family of target molecules. They exhibit a range of affinities (KD in the pM to μM range), with variable levels of off-target binding and are sometimes classified as chemical antibodies. Aptamers and antibodies can be used in many of the same applications, but the nucleic acid-based structure of aptamers, which are mostly oligonucleotides, is very different from the amino acid-based structure of antibodies, which are proteins. This difference can make aptamers a better choice than antibodies for some purposes. Two kinds of aptamers are emerged:

1) Nucleic acid-based aptamers, which are short sequences of artificial DNA (DNA aptamer), RNA (RNA aptamer), XNA (XNA aptamer, i.e. bases with synthetic nucleic acid analogues that have a different backbone than the ribose and deoxyribose found in the nucleic acids of naturally occurring RNA and DNA); Nucleic acid-based aptamers (DNA aptamers and RNA aptamers or modified XNA aptamers) are small, highly structured DNA/RNA molecules, isolated from combinatorial libraries by Systematic Evolution of Ligands by Exponential Enrichment (SELEX). They have affinities for their target molecules similar to how antibodies work. Aptamers have demonstrated great potential to replace antibodies in biosensors, point-of-care diagnostics, therapeutics, and all areas currently dominated by antibodies.

2) Peptide aptamers which are small combinatorial peptides that are selected to bind to specific sites on their target molecules, consisting of short, 5-20 amino acid residues long sequences, typically embedded as a loop within a stable protein scaffold. Peptide aptamers were isolated from combinatorial display libraries, such as phage display library, by various display techniques, such as phage display biopanning.

Once aptamers are identified, they can be produced for less than 10% of the cost for producing antibodies. Oak BioSciences provides a broad range of unique aptamer screening services for custom aptamer development assays.

  • RNA aptamer screening by SELEX
  • DNA aptamer screening by SELEX
  • XNA aptamer screening by SELEX
  • Peptide aptamer screening by Phage Dispaly
  • Affibody screening by Phage Dispaly
  • Mimotope screening by Phage Dispaly
  • Cell-specific aptamer screening (Cell-SELEX)
  • Aptamer screening for protein/antibody binding
  • Aptamer screening for peptide binding
  • Aptamer screening for RNA binding
  • Aptamer screening for small molecule binding by Capture SELEX
  • Aptamer screened for DNA-binding protein binding

For detailed pricing information, please fill the form below for a custom quotation!

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Aptamer and affibody Development Services