Our mesoscopic oblique plane microscope is online: It enables rapid volumetric imaging of a whole zebrafish embryo with ~2.3 micron lateral resolution. This is enabled by merging a couple of optical innovations and tricks. 1/N

Most importantly, the tilt angle of the light-sheet, which is usually dependent on the numerical aperture of the objective, is increased by total internal reflection in a glass prism, on which the sample sits. Schematic of the setup left, experimental prism on the right. 2/N

A transmission grating bends the fluorescence light into the tertiary objective, an idea that was pioneered by @benjulab. This works quite well for OPM systems in a specific range of numerical apertures and tilt angles, which correspond well to mesoscopic imaging. 3/N

Further innovations include an image based galvo scanning mechanism and optical tiling for OPM. The latter allows us to image tall volumes (on the order of 1mm) with decent 3D resolution. A column of beads in Agarose is shown below. 4/N

I love bead imaging, but here is an example of imaging the vasculature in a zebrafish embryo. 5/N

Since it is an open top imaging system, one can put multiwell plates on it. Here are a couple of zebrafish xenografts imaged in a 96 multiwell plate. A-H are projection images, the last row is from a 3D stack that was acquired in the tail of the fish shown in A. 6/N

Functional volumetric imaging in an instar 1 larva (muscle cells labeled with a GCaMP sensor). 7/N

So pretty in vivo imaging 👏👏👏I’d like to know what’s different in Adam’s and Elizabeth’s systems. I’m lost in so many developments of 💡-sheets.

I tried to summarize some of the innovations in the tweetorial (tweet thread).

Very cool systen, Reto! Congratulations!

Thank you. It is a rather easy to build system, and it images nicely.