To quantitate biotin, we offer two kits as follows:
Biotin Quantitation Kit (Cat. No. 28005): With this kit, a solution containing the biotinylated protein is added to a mixture of HABA reagent (4’-hydroxyazobenzene-2-carboxylic acid and avidin. Because of its higher affinity for avidin, biotin displaces the HABA and the absorbance at 500nm decreases proportionally. Fluorescence Biotin Quantitation kit (Cat. No. 46610): This microplate-based biotin assay is easy to perform by adding the supplied fluorescent reporter to the biotinylated samples and diluted biocytin standards. The avidin fluoresces when the weakly interacting HABA (4’-hydroxyazobenzene-2-carboxylic acid) is displaced by the biotin. The amount of biotin is determined by comparing the sample's fluorescence to the biocytin standard curve. This assay requires must less sample volume than the microplate colorimetric HABA assay and is much more sensitive To determine the dye-to-protein ratio after fluorophore conjugation, absorbance readings of the protein:dye conjugate are taken and the molar ratio can then be calculated. Please go to this Tech Tip (https://tools.thermofisher.com/content/sfs/brochures/TR0031-Calc-FP-ratios.pdf")for more information
Find additional tips, troubleshooting help, and resources within our Protein Purification and Isolation Support Center.