<p>(A) Schematic overview of measured binding/internalization status of fluorescent labeled antibodies. (B) Flow cytometric internalization analysis of WT nBT062, stable nBT062, half nBT062 and bispecific nBT062-natalizumab. CD49d was blocked by 50x excess of unlabeled natalizumab. Data represent median fluorescence intensity values of at least three separate experiments. Column colors represent antibody location as shown in (A). ****p<0.0001, ***p<0.001. (C) Fluorescence microscopy of BaF3-hCD138 (CD138<sup>+</sup>) cells (I-V) or BaF3 (CD138<sup>-</sup>) control cells (VI) incubated for 3h with indicated Dylight-448 labeled nBT062 model antibodies or natalizumab (green, a). Lysosomal-associated membrane protein-1 (LAMP-1) is shown in red (b), nucleus is shown in blue (c). Respective overlay pictures are demonstrated (d).</p