2.8. Determination of Nucleus Nrf2 Using the Immunofluorescence Staining Method

The paraffin samples (5 μm) were removed from the sections with xylene, rehydrated in graded alcohol series, subjected to antigen retrieval in EDTA buffer (pH 8.0, Goodbio technology) using a microwave, and then placed in 3% BSA to block nonspecific staining for 30 min at room temperature. After that, the sections were incubated with anti-Nrf2 antibody (1 : 100, Goodbio technology) at 4°C overnight, followed by the fluorescent-labeled secondary antibody at lucifuge and room temperature for 50 min (1 : 300; Goodbio technology). After counterstaining with DAPI haematoxylin, the sections were dehydrated and viewed under a fluorescence microscope (400× amplification; Nikon). The ultraviolet excitation wavelength was 330–380 nm, the emission wavelength was 420 nm, the CY3 red light excitation wavelength was 510–560 mm, and the emission wavelength was 590 nm.