The effect of 600 μM ligand on the non-reducing SDS-PAGE banding pattern for the intact h2E2 mAb and its Fc fragment. 10 μL, containing 2 μg of each sample was loaded in each well of a 7% acrylamide non-reducing SDS-PAGE gel, and stained with Coomassie blue. The red dashed lines indicate the electrophoretic migration positions of the totally denatured proteins (proteins boiled for 5 min in the SDS sample buffer without a reductant). The ligand included in each sample is indicated at the top of each sample well: None, no ligand; COC, cocaine; CE, cocaethylene; BE, benzoyl ecgonine; NC, norcocaine, EME, ecgonine methyl ester; EG, ecgonine. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)