Custom DNA Aptamer Synthesis

BOC Sciences offers high-quality custom DNA aptamer synthesis services using a sequence design and optimization process. BOC Sciences' aptamer specificity and affinity testing service platform is powered by a standardized process and diverse assay technologies.

Fig 1. Schematic representation of DNA aptamer selection. (Sefah et al., 2010)

What is DNA Aptamer?

DNA Aptamer is a special class of artificial nucleic acid molecules composed of DNA molecules. It was selected from a large DNA library by in vitro evolutionary techniques. The unique properties of DNA Aptamer stem from its structural diversity and stability. DNA Aptamer can interact specifically with target molecules by forming different secondary and tertiary structures. Moreover, DNA Aptamers are inexpensive to synthesize, easy to modify, and can be adapted easily. Using DNA aptamers for biosensing, drug delivery, diagnostics, and therapeutics are just some of the applications that are possible with these molecules because they can recognize and bind to targets molecules.

Customization of DNA Aptamer

• Optimization and Design of DNA Aptamer

(1) Library design: The design of a DNA Aptamer requires the design of a starting library, which contains a large number of different DNA sequences, usually consisting of random nucleotides, and usually between 30-100 nucleotides in length.

(2) Screening: After the design of the DNA Aptamer, it needs to be screened, which can be done using SELEX technology. After several rounds of binding and separation steps, DNA Aptamer sequences with high affinity and specificity can be screened.

(3) Optimization: During the screening process, the structure and properties can be determined by sequencing analysis. Sequences possessing the desired properties can be retained and the DNA Aptamer sequence can be optimized and modified. The steps of modification include:

• Introduction of point mutations or localized mutations.
• Modification by chemical modification or modification of paired bases.
• Adjusting the length of the DNA Aptamer by increasing or decreasing the number of nucleotides.

After the above modifications, the characteristics of DNA Aptamer such as structure, affinity and stability can be changed.

(4) Functional validation: The optimized DNA Aptamer needs to be functionally validated to evaluate its performance and effectiveness in specific applications.

• Synthesis of DNA Aptamer

DNA Aptamer is easy to produce by chemical synthesis, has desirable storage properties, and produces little or no immunogenicity for therapeutic applications. Synthesis of DNA Aptamer is typically performed using solid-phase synthesis methods. In solid phase synthesis, the DNA molecule is constructed nucleotide by nucleotide from the 5' end to the 3' end. During synthesis, each nucleotide in the form of its protecting group reacts with the 3' hydroxyl group on the solid phase support, followed by steps such as deprotection, washing and coupling. These steps are repeated until the synthesis is complete.

During the custom synthesis of DNA Aptamer, some additional modifications or labeling may be required for specific applications, such as the introduction of fluorescent markers, biotin markers, to achieve specific functionality or to facilitate subsequent use in applications.

BOC Sciences provides customized DNA aptamer synthesis services that enable customers to quickly and accurately prepare aptamers with high affinity and specificity, saving costs for their experimental projects. We provide one-stop in vitro aptamer screening service by utilizing the natural evolution of ligand systems through exponential enrichment (SELEX) method.

Reference

1. Sefah K, et al. Development of DNA aptamers using Cell-SELEX[J]. Nature protocols, 2010, 5(6): 1169-1185.