Our labeling reagent reacts with a primary amine group on any biomolecule. Therefore, in order to biotinylate your oligo, you would have to have it synthesized with an amino modification on either the 3′ or 5′ end. Most oligo companies can directly add a biotin onto the nucleotide as easily as they can add a primary amine group. The ChromaLink™ reagent, would therefore require an extra step and while it would be slightly more quantifiable – you could determine EXACTLY how many biotins/oligo- a mass spec from the oligo synthesis would provide similar information. In general, for biotinylation of proteins, peptides, or other amine-containing molecules, we recommend our product with confidence, but for oligos, we would just have the oligo synthesized with the biotin group.