The function of biotin modification in oligonucleotides is primarily for affinity-based applications, particularly in molecular biology, biochemistry, and biotechnology. Biotin, a small molecule, is covalently attached to the oligonucleotide, typically at one end or at specific positions within the sequence. This modification imparts several functional advantages:

1. Affinity purification: Biotin-modified oligonucleotides can be used to selectively capture or purify target molecules from complex mixtures. Biotin has a high affinity for avidin or streptavidin, proteins that bind biotin with exceptional specificity and affinity. By attaching biotin to oligonucleotides, researchers can easily isolate and purify nucleic acids, proteins, or other biomolecules that interact with the biotinylated oligo.
2. Detection and quantification: Biotin-modified oligonucleotides are widely used as probes in various detection assays, such as enzyme-linked immunosorbent assays (ELISA), Southern blotting, Northern blotting, and in situ hybridization. Biotinylated oligos can bind to avidin or streptavidin conjugated to reporter molecules (e.g., enzymes, fluorophores, or nanoparticles), allowing sensitive detection and quantification of target molecules.
3. Biotin-streptavidin bridging: Biotin-modified oligonucleotides can facilitate specific interactions between different molecules by acting as a linker. For instance, biotinylated oligos can be used to bridge interactions between nucleic acids, proteins, or other biomolecules conjugated to streptavidin. This strategy is commonly employed in nucleic acid assays, protein-protein interaction studies, and biosensing applications.
4. Surface immobilization: Biotin-modified oligonucleotides can be immobilized onto solid surfaces (e.g., microarrays, beads, or plates) coated with avidin or streptavidin. This immobilization strategy enables high-density array fabrication, spatially resolved detection, and multiplexed analysis of nucleic acids, proteins, or other targets.
5. Targeted delivery: Biotin-modified oligonucleotides can be employed for targeted delivery of therapeutic agents, such as siRNA or antisense oligonucleotides. Conjugation of biotin to oligos enables specific binding to biotin receptors overexpressed on the surface of target cells, facilitating cellular uptake and enhancing the therapeutic efficacy of the cargo.

Overall, biotin modification of oligonucleotides offers versatile tools for a wide range of research and practical applications, enabling specific and sensitive detection, purification, and manipulation of biomolecules.

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.