Nucleic Acid Aptamer (DNA Aptamer, RNA Aptamer, XNA Aptamer) Development Services

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). Nucleic acid aptamers are short oligonucleotide sequences and are able to fold into well-defined three-dimensional structure via specific conformational changes and show strongly bind to their targets with high affinity and specificity. For peptide aptamer development, please click another page.

Nucleic acid aptamers have several advantages with respect to antibodies. Once the aptamers are selected, they can be further synthesized within just a few days in a controlled fashion with high purity and reproducibility. Additionally, aptamers are highly chemically stable over a wide temperature range, retain most of their functionality even after multiple regeneration steps, and can be isolated by in vitro selection without immune response. As oligonucleotides can be easily modified with different reactive chemical groups, their immobilization on surfaces can be easily controlled. Thanks to such flexibility, aptamers are very popular for the design and optimization of novel biosensors.

DNA aptamers and RNA aptamers are newly emerged sensing elements that are competitive with or sometimes even better than antibodies due to their various advantages: a compact size, cost effectiveness, chemical stability, in vitro synthesis, easy modification, labeling and so on. Therefore, there have recently been intensive advances in aptamer-based biosensors including electrochemical aptasensors that are more proper to the miniaturization and integration of biosensors for high-throughput analysis and point-of-care (POC).

Fusion Biolabs offer five strategies for SELEX:

1)  Magnetic Beads-based SELEX (target biotinylated via streptavidin beads; target directly conjugated to the beads; tagged target tagged via affinity beads).

2)  Capture-SELEX (Aptamer SELEX through ssDNA Library Immobilization)

3)  GO-SELEX (Graphene Oxide-SELEX) and Gold-SELEX (gold nanoparticles (AuNPs) -SELEX)

4)  Cell-SELEX (for both mammalian cells and bacterial cells)

5)  Bio-SELEX (biomarkers identification directly from biological samples)

The criteria for any of the methods is no change to structure of the target, so the aptamer is specific binding to the target only.

Aptamer candidates with high enrichment, low free energy level and the large difference in the secondary structure (different family groups) will be selected for binding affinity test.

Deliverables

1) Sequences of candidate aptamers and small-scale synthesis (5-16 candidate aptamers)
2) Full project report (screening procedures and validation data)

Ordering Information

Nucleic Acid Aptamer Development Services

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