Fig 1: Internalization and lysosomal trafficking. MW282 mAb, 9MW2821, and EV were labeled with Alexa Fluor 488 using a commercial Alexa Fluor 488 conjugation kit (Abcam, catalog No. ab236553). A, Internalization and lysosomal trafficking of 9MW2821 in PC-3/nectin-4 cells, stained for lysosomes (red) and 9MW2821 (green). Costaining of lysosomes and 9MW2821 observed as yellow. Scale bars, 100 µm. B and C, Fluorescence signal increased as drugs accumulated intracellularly. Alexa Fluor 488–labeled MW282 mAb, 9MW2821, and EV were internalized and stored continuously in PC-3/nectin-4 (left) and MDA-MB-468 (right). Fluorescence signals are mean values of triplicate measurements for each cell line.