(Abcam, ab208943, Rabbit pAb, 1:100) or isotype control (Abcam ab37415 anti-Rabbit IgG, 1:1000) for 1h in permeabilization/blocking buffer. Cells were washed 3x5min with PBS then incubated with the AlexaFluor488-labeled secondary antibody (Abcam, ab150077 Goat pAb to Rb IgG, 1:500) for 1h in permeabilization/blocking buffer. Then cells were washed 3x5min with PBS and slow-fade gold reagent (Gibco, S36939) was added dropwise to the wells. A coverslip was applied and secured with nail polish. Cells were imaged using a Zeiss LSM880 microscope at 63X magnification with oil.