Three-dimensional side-view endomicroscope for tracking individual cells in vivo

We demonstrate a side-view endomicroscope using a monolithic 3-axis scanner placed in the post-objective position that performs either tilt or piston motion to achieve either optical scan angles >10° or large vertical displacements, respectively. This configuration allows for scaling down of instrument dimensions for high maneuverability and accurate positioning in vivo. Images exceeded either 700 × 600 μm2 in the horizontal plane or vertical depths of 200 μm. Resolution of 1.19 and 3.46 μm was obtained in the horizontal and oblique planes, respectively. Optical sections were collected from dysplastic colonic epithelium in vivo in mice that express tdTomato at 10 Hz to visualize individual cells.