2.7  Immunofluorescence
Cells were incubated with Nrf2 primary antibody in PBS containing 1% BSA (1:200) for 1 h at 37 °C and then treated with Alexa Fluors 488 goat anti-rabbit antibody (KeyGen, Nanjing, China). Nuclei were visualized with DAPI (Santa Cruz, Texas, USA). Images were acquired by inverted fluorescence microscope (Nikon, Japan).