Blockade of BoNT/A uptake and SNAP-25 cleavage by BeAb, CR2 IgG and 2G11 IgG. (A) Ability of the indicated antibody to block uptake of BoNT/A into rat hippocampal primary neurons. Mixtures of BoNT/A1 and the indicated antibody shown were mixed, incubated with neurons for 30 min, stripped from the cell surface, the cells permeabilized and intra-neuronal BoNT/A detected using mAb(s), indicated. B Ability of the indicated antibody to block SNAP-25 cleavage. BoNT/A1 (1 nM) and the indicated antibody shown were mixed, incubated with neurons for 30 min, the cells lysed, and the lysate run on SDS-PAGE followed by Western blotting using an antibody specific for SNAP-25.