*4.3. Immunofluorescence Microscopy*

Cells were grown on coverslips prior to the performance of experiments. Cells were fixed with cold methanol at −20 ◦C for 6 min. Then, the cells were washed with PBS three times followed by blocking with 5% BSA for 1 h. After blocking, cells were incubated with antibodies overnight at 4 ◦C. Then, cells were washed with PBS three times and incubated with FITC-conjugated and/or Cy3-conjugated secondary antibodies (Invitrogen, Carlsbad, CA, USA) for 1 h at room temperature in the dark. After extensive washing, the cover slips were mounted in 50% glycerol (in PBS) on glass slides. Cells were observed with an AxioImager M2 fluorescence microscope (Zeiss, Switzerland).
