Oligo Biotin Labeling

Biotinylated Oligonucleotides

Bio-Synthesis offers biotinylated oligonucleotides for RNA and DNA detection or isolation application due to its high affinity toward strepatvidin. Biotinylated oligonucleotides can be used to attach specifically to streptavidin-enzyme-conjugates, to streptavidin-protein-conjugates, to strepavidin coated surfaces or to streptavidine-dye-conjugates. Applications using biotinylated oligonucleotides include:

• Immuno assay
• Chemiluminescence assays
• Fluorescence in-situ hybridisation FISH
• Immunohistochemistry
• Straptavidin affinity chromatography
• Magnetic bead capture for cDNA screening

Biotin (or vitamin H) is a small biologically active molecule with a molecular weight of 244,31 Da. It acts as a co-enzyme in living cells. Biotin can be coupled to oligonucleotides at the terminal and internal position at multiple sites.  Iin 2000, Sabnayagam et al have shown that the size of the DNA or RNA oligonucleotide covalently attached to biotin seems to limit the binding capacity to immobilized streptavidin and the ability to capture large DNA fragments with magnetic streptavidin beads was directly correlate to the arm length of the biotin. Therefore, we also offer long chain biotin to increase binding capacity of large DNA fragment, improve binding kinetics and the accessibility to enzymatic events  at the solid phase surfaces¹.

One drawback of using biotinylated oligonucleotide in the detection system is the likelihood to obtain high backgrounds due to the presence of natural biotin in living cells. Alternate detection methods are the use of  digoxigenin/antidigoxigenin assays or enzyme/substrate assays that require labelling of the oligonucleotide with Digoxigenin or HRP (Horseradish-Peroxidase). Bio-Synthesis also offers dignoxigenin oligonucleotide labeling and HRP-oligonucleotide conjugation services.

Reference

1. Sabanayagam et al., Nucleic Acids Res., 2000, 28, e33