IHC staining of EGFR protein on F98-EGFR tumor slides. F98-EGFR tumors were snap-frozen in O.C.T. ? compound and sectioned at 4-μm thickness. After fixation and permeabilization, cells were incubated with rabbit anti-EGFR mAb (CST), followed by detection with VRDye? 549 Goat anti-Rabbit IgG. DAPI was used to stain the nuclei. Image acquired on Olympus IX81 microscope.