A few years ago we got a Nikon AZ100 microscope on indefinite loan from a lab here that no longer was using. The AZ100 is an interesting microscope – it has low magnification objectives with relatively high numerical apertures (we have 1x / 0.1, 2x / 0.2, and 5x / 0.5 objectives) combined with a 1x – 8x optical zoom system to allow both large field-of-view imaging and high resolution imaging of the same sample. I initially set this up for routine fluorescence imaging, but it didn’t fill a useful niche and so largely went unused.
As groups on campus began testing various tissue clearing methods (CLARITY , PACT , iDISCO , …), I realized that this would make a good base for a simple “Ultramicroscope”-style  light sheet microscope. This is about the simplest kind of light sheet microscope you can build; you simply use a cylindrical lens to reshape an expanded laser beam to a sheet that propagates perpendicular to the optical axis of the microscope. We had an old 561 nm Coherent Sapphire laser sitting around from a rebuild of the laser launch on our spinning disk confocal, so a few hundred dollars in Thorlabs parts sufficed to set up a demo system. The sample is placed in a cuvette on the microscope stage, illuminated with the light sheet from the side, and imaged with the objective from above.
The initial light sheet test system. The laser is mounted on the black table; to the left you can see the mirrors used to direct the beam to propagate through the image plane, perpendicular to the optical axis. The cage system holds a Galilean beam expander and a slit; the cylindrical lens sits inside the dark enclosure. In the inset you can see the cylindrical lens and fluorescence excited in an agarose cylinder doped with fluorescent beads.
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