Structured Illumination Microscopy.

Fixed cell 3D-SIM was performed using the DeltaVision OMX SR imaging system (GE Healthcare) outfitted with a 60× 1.42 NA oil-immersion objective lens. Samples were fixed in cold methanol and imaged in PHEM buffer at room temperature using a refractive index number 1.518 immersion oil. The final pixel size is 40 nm, with 125-nm z-plane spacing using 3 rotations of the SIM grating. SIM processing was performed using the AcquireSRsoftWoRx acquisition and analysis software, and multicolor images were channel aligned using a matrix generated with Tetraspeck beads.