Immunohistochemical Analysis of PSMA Expression

After the last scan, two mice/cell line xenografts were sacrificed and tumors were collected for immunohistochemical (IHC) evaluation of the PSMA expression levels as previously reported^{28 (link)}. In short, sections were taken from the center of the tumor sample and stained using Haematoxylin/Eosin, incubated with a primary PSMA antibody (1:400, 2 h, ab133579, Abcam) and counterstained using Haematoxylin (Mayer). Sections were digitally scanned with a virtual scanning microscope (Olympus BX51, Olympus Belgium SA/NV, Berchem, Belgium) at high resolution (20 × magnification).