Characteristics of dual-conjugated antibody: (A) Schema of IR700-conjugated antibody and dual-conjugated antibody. (B) Validation of covalently bound IR700, IR800, and ICG-EG4 to trastuzumab by SDS-PAGE (from left to right: colloidal blue staining, merged fluorescence image, IR700 channel, IR800 channel). (C) Comparison of the in vitro therapeutic effect of NIR-PIT. Cell viability was measured by PI staining. In each light exposure dose, there was no significant difference among the Tra-IR700 group, Tra-IR700/IR800 group, and Tra-IR700/ICG-EG4 group. Data are shown as mean ± SEM (n = 4).