ReadiLink? Protein Biotinylation Kit. Biotin is widely used for labeling biomolecules, in particular, antibodies. Our ReadiLink? Protein Biotinylation Kit is optimized for the preparation of biotin-labeled IgG for enzyme immunoassay (EIA). It uses biotin succinimidyl ester that reacts with the amino groups of IgG and other biomolecules. This kit comes with all the necessary reagents for labeling and purification. On our hands, 3 to 6 biotin molecules can be conjugated to each IgG molecule depending on the molecular weight and lysine residues available on the IgG molecule. The kit can be used for 2 conjugation reactions. For each conjugation reaction the material can label up to 1 mg protein. The entire process only takes less than an hour.