- We typically recommend an antibody concentration of at least 1 mg/mL for the biotinylation reaction. If infeasible to concentrate your IgG four fold, then increase the molar equivalents to 30 so that you can have a final MSR between 5 and 8. If you have a method of concentrating your antibody (e.g., Vivaspin Diafiltration filters, Cat. No. S-4004-010), I would recommend that first, then adding 20 equivalents of the ChromaLink™ reagent.