2P ISIM enables super-resolution imaging in volumes of ~100 μm thickness. (a) Rendering of ~60 × 60 × 110 μm volume (eye of 38–40 h old, live zebrafish embryo) captured with 2P ISIM. Single microtubules, bundles of microtubules, and dividing cells (magenta arrows) are visible in the volume. See also Media 4. (b), (d), (f) XY slices at indicated axial (Z) distance from the base of the stack. See also Media 5. Scale bar: 10 μm. (c), (e) Higher-magnification views of the yellow regions in (b), (d), emphasizing thin filaments (yellow arrows) with apparent width <200 nm. Scale bar: 5 μm. (g) XZ slice at indicated lateral (Y) distance from the origin of the stack, emphasizing concentric, circular cytoskeletal organization within the eye. Scale bar: 10 μm. All data presented in this figure were deconvolved.