Ex vivo verification of PSMA expression in DU145-PSMA and DU145 tumours. Immunofluorescence staining of tumour cryo-sections was performed using J591Cdia-AlexaFluor-488 (green). Nuclei are counterstained with DAPI (blue). Three representative tumour sections are shown. All analysed DU145-PSMA sections showed strong, heterogeneous staining for PSMA. No staining was observed in DU145 tumour sections.