A novel18F-labeled clickable substrate for targeted imaging of SNAP-tag expressing cells by PETin vivo

Abstract

Bioorthogonal covalent labeling with self-labeling enzymes like SNAP-tag bears a high potential for specific targeting of cells for imagingin vitroand alsoin vivo. To this end, fluorescent SNAP substrates have been established and used in microscopy and fluorescence imaging while radioactive substrates for the highly sensitive and whole-body positron emission tomography (PET) have been lacking. Here, we show for the first time successful and high-contrast PET imaging of subcutaneous SNAP-tag expressing tumor xenografts by bioorthogonal covalent targeting with a novel18F-based radioligandin vivo.