Fig. 4From: A tool for nuclear imaging of the SARS-CoV-2 entry receptor: molecular model and preclinical development of ACE2-selective radiopeptidesRepresentative HPLC chromatograms of the radiopeptides prepared at variable molar activities (20–80 MBq/nmol). A [67Ga]Ga-DOTA-DX600; B [67Ga]Ga-NODAGA-DX600 and C [67Ga]Ga-HBED-CC-DX600. The retention time (tR) of un-coordinated (“free”) gallium-67 was ~ 2.5 min; the tR of radiopeptides was ~ 9.0 minBack to article page