Immunocytochemistry using IDE antibodies 6A1 and 6H9. A, B, Immortalized hepatocytes from wild-type (A) and IDE-KO (B) mice immunolabeled with 6A1 (green, 10 μg/mL) and visualized under identical conditions by laser confocal microscopy (100× magnification). Nuclei are stained with propidium iodide (red). Note the complete absence of 6A1 immunoreactivity in IDE-KO cells (B). C, CHO cells transiently transfected with human IDE cDNA, labeled with 6H9 (green, 20 μg/mL). Nuclei are stained with DAPI (blue). Note absence of 6H9 immunoreactivity in non-transfected cells. D, HeLa cells stained with 6H9 (green, 10 μg/mL), showing that this mAb can detect endogenous levels of human IDE. Images in Cand Dwere acquired using conventional fluorescent microscopy (20× magnification).