Purification of the BoNT/B complex

aThe concentration of total BoNT/B complex was determined by a “sandwich” ELISA method using the purified BoNT/B as a standard. And the purified BoNT/B concentration was determined by BCA assay.bMinimum lethal dose (MLD) was defined as the minimum dose required to kill two mice as described in Materials and Methods.cThe purification factor was estimated by the mouse toxigenicity test of BoNT/B complex.