Fig. 3

Ex vivo confocal imaging of brain vasculatures of a mouse injected with p-FE. a Photo and wide-field NIR-II epi-fluorescence imaging of brain in a mouse injected with p-FE (808 nm excitation, emission >1200 nm) with exposure time of 5 ms. b–d Ex vivo confocal imaging of brain in a mouse injected with p-FE (785 nm excitation, emission >1100 nm, laser power ~30 mW, PMT voltage ~500 V). b Small area (200 × 200 µm, x × y, step size: 1 µm) and c Large area (3000 µm × 2000 µm, x × y, step size: 1 µm). The deepest area could reach ~1350 µm. d 3D reconstruction of vasculatures in brain: small area (left side, 200 µm × 200 µm × 200 µm, x × y × z, step size: 1 µm along x, y, and z directions, galvo mirror scanning, scanning speed: 2 s/frame) and large area (right side, 400 µm × 400 µm × 400 µm, x × y × z, step size: 2 µm along x and y directions, 2.7 µm along z direction, stage scanning, scanning speed 7.5 min frame⁻¹). Scale bar represents 6 mm