I want to quantify a biotin-protein conjugate after chemical biotinylation. After biotinylation, the solution contains both biotinylated protein and free biotin.
I intend to use a HABA-avidin biotin quantitation kit like this one from Pierce. Since the biotinylated protein and the free biotin will both displace HABA and decrease the absorbance, I need to remove the free biotin so that I only quantify the biotinylated protein.
How do I separate the free biotin from the solution?