
Keywords: CCK4, Trp-Nle-Asp-Phe-NH2; Cl-HOBt, 1-hydroxy-6-chlorobenzotriazole; CuAAC, copper-catalyzed azide–alkyne cyclization; DELFIA, dissociation-enhanced lanthanide fluoroimmunoassay; DIC, diisopropyl carbodiimide; DMEM, Dulbecco’s Modified Eagle Medium; DTPA,