Oligonucleotide base modification is the introduction of different chemical modifications on the bases of oligonucleotides to change their properties and functions. The following are some common types of oligonucleotide base modifications:

1. Methylation: Addition of a methyl group to nitrogen or oxygen atoms in the base. Methylation modifications can enhance oligonucleotide stability, alter DNA unwinding properties, and affect DNA-protein interactions.
2. Phosphorylation: Introduction of a phosphate group onto the base. Phosphorylation modifications play important roles in biological processes such as signal transduction, gene expression regulation, and DNA repair.
3. Amination: Introduction of an amino group onto the base. Amination modifications are used in applications such as labeling primers and probes, fluorescent labeling, etc.
4. Biotinylation: Introduction of a biotin moiety onto the base. Biotinylation modifications are commonly used in oligonucleotide detection, purification, drug delivery, etc.
5. Hydroxymethylation: Introduction of a hydroxymethyl group onto the base, typically in addition to methylation modifications. Hydroxymethylation modifications play important roles in epigenetic research.
6. Deoxyribosylation: Introduction of an acetyl group onto the sugar moiety of the base. Deoxyribosylation modifications can alter the oligonucleotide's charge properties and solubility.
7. Locked Nucleic Acids (LNA): Introduction of a methylene bridge between the 2' and 4' positions of the sugar moiety. LNA modifications enhance the oligonucleotide's affinity and stability.
8. Ribose Modification: Chemical modifications of the oligonucleotide's sugar moiety, such as 2'-O-methylation, 2'-O-acetylation, etc. These modifications can enhance the oligonucleotide's stability and affinity.

GenCefe provides customized DNA oligo modification/labeling services, including more than 100 modifications such as biotin, digoxigenin, phosphate, thiol, sulfhydryl, amino, special bases, and a variety of fluorescent groups. 100% of the delivered modified probes/primers have passed mass spectrometry detection to ensure accuracy and purity, meeting the needs of scientific research and industrial-grade modified primers/probes.