Structure of DNA

DNA, a polymer, is composed of a repeating series of monomer sequences. The nucleotide monomer units construct DNA. Each nucleotide in DNA contains a deoxyribose, a nitrogen-containing base, and a phosphate group. Deoxyribose and phosphate components are shared by all nucleotides, while the nitrogen-containing bases are different and classified into four types. These bases are divided into two main groups: purinic and pyrimidinic. The diverse arrangement of these bases regulates the production of specific proteins and enzymes in a cell. The DNA molecule has two strands that coil around each other to form a double helix. The two DNA strands have opposite directions and form a helical spiral. They wind around a central axis in a right-handed spiral. The individual nucleotide bases are positioned on the inside of the helix, stacked on top of each other like steps of a spiral staircase.

Fig.1 The structure of DNA. (Wikipedia, 2023)

Key Technologies

Our service is built on the gold standard of DNA synthesis: phosphoramidite chemistry. This highly efficient and well-established method allows for the sequential addition of nucleotide bases to a growing DNA chain. The process begins with the modification of nucleosides into stable phosphoramidite monomers, which are then used in a cyclical reaction. To prevent unwanted side reactions, protecting groups are strategically used on the phosphoramidite molecules, providing tight control over the synthesis process.

Chemical Synthesis, Glyco-Perfected: DNA Built to Deliver.

CD BioGlyco offers the phosphoramidite method that is combined with the application of solid-phase technology and automation for the synthesis of DNA. This synthesis occurs in the opposite direction (3' to 5') compared to DNA biosynthesis in DNA replication (5' to 3'). During each synthesis cycle, one nucleotide is added.

• At the start of DNA synthesis, the first protected nucleoside is already attached to the resin. The support-bound nucleoside is equipped with a 5'-4,4'-dimethoxytrityl (DMT) protecting group. Its purpose is to prevent polymerization during resin functionalization. Before DNA synthesis continues, this protecting group needs to be removed from the support-bound nucleoside through detritylation.
• After detritylation, the support-bound nucleoside becomes primed for the reaction with the next base. The next base is introduced in the form of a nucleoside phosphoramidite monomer.

Fig.2 The steps of coupling reaction. (CD BioGlyco)

• Subsequently, to prevent deletion mutations, we incorporate a capping step following the coupling reaction.

Fig.3 The steps of the capping reaction. (CD BioGlyco)

• During the coupling step, the phosphite-triester is formed and is not stable in acidic conditions. Therefore, we convert it into a stable species before proceeding to the next detritylation step. We utilize iodine oxidation in the presence of water and pyridine to achieve that. The resulting phosphotriester is essentially a DNA backbone that is protected with a 2-cyanoethyl group. The cyanoethyl group stops undesirable reactions at the phosphorus in later synthesis stages.
• We remove the DMT protecting group at the 5'-end of the resin-bound DNA chain after phosphoramidite coupling, capping, and oxidation, in order to allow the primary hydroxyl group to react with the next nucleotide phosphoramidite. The cycle is repeated for each base to generate the desired DNA.

Workflow

Publication Data

Applications

• DNA testing is useful for pathogen identification, detection of biological remnants in archaeological excavations, tracing disease outbreaks, and examining human migration patterns.
• DNA can be used in diagnostics, the development of new vaccines, and cancer therapy.
• DNA can be used in identifying genetic predispositions to certain diseases.

Advantages

• Our method involves using large excesses of solution-phase reagents to rapidly drive reactions to completion.
• Our method doesn't need purification after each step since impurities and excess reagents are thoroughly rinsed away.
• Our process is easily automated on computer-controlled solid-phase synthesizers.

Frequently Asked Questions

Associated Services

Our chemical DNA synthesis delivers precisely engineered DNA fragments tailored to your sequence requirements. To ensure these synthetic oligonucleotides achieve the rigorous purity standards demanded by sensitive downstream applications, whether for CRISPR editing, PCR assays, or therapeutic development, we provide comprehensive Oligonucleotide Fragment Purification Services. These methods selectively isolate full-length sequences while removing failure products and impurities:

CD BioGlyco possesses extensive expertise in the field of DNA synthesis. We not only provide clients who require targeted synthesis for specific DNA sequences but also the Synthesis of Modified DNA Molecules. Our advanced technology and exceptional research team are well-equipped to fulfill your requirements. Our primary goal is to provide clients with high-quality custom DNA synthesis solutions. We encourage clients to contact us, as we eagerly await the opportunity to assist our clients.