An In Vitro Assay to Assess CAR T Cell Cytotoxicity against Tumor Spheroids

Source: Dillard, P., et al. A Spheroid Killing Assay by CAR T Cells. J. Vis. Exp. (2018) This video demonstrates an in vitro assay evaluating the cytotoxic effects of CAR T cells on 3D tumor spheroids expressing fluorescent proteins. This assessment utilizes the Annexin V red fluorescent probe, which binds to exposed phosphatidylserine residues on the outer leaflet of apoptotic cancer cells after interactions with CAR T cells. The red fluorescence emitted by the probe aids in distinguishing these cells from healthy ones emitting green fluorescence.