High throughput gentle imaging of cells, embryos and organoids with an inverted lattice light sheet microscope.

The Cambridge Advanced Imaging Centre (CAIC) is a bioimaging research facility at the University of Cambridge. It provides researchers across the region, nationally and internationally with access to state-of-the-art microscopes. CAIC enhances the value generated by microscopes by acting as a hub for physicists, engineers, computer scientists, chemists and biologists to work together. Since opening in 2013, CAIC has kept pace with technology advances by directly developing microscopes and improving access to equipment among departments, institutes and industry. In order to maintain excellence, CAIC continually identifies and implements cutting-edge imaging methods that meet the pressing needs of the region's imaging community.

In this project we will install a novel inverted lattice light sheet microscope into CAIC. This equipment will fill a critical gap in our national live imaging portfolio, establishing a capability that will deliver world leading excellence in live imaging of cells and embryos. The hallmark of light sheet microscopy is a significant reduction in damage caused by light to the specimen under observation when compared to gold-standard confocal microscopes. This benefit is offset by reduced resolution and cumbersome sample mounting protocols which limit use. At CAIC we are keenly aware of these limitations, having developed two customised upright and horizontal light sheet microscopes. These barriers to widespread adoption have been eliminated by a novel microscope - the inverted lattice light sheet microscope. This new technology has an innovative lens system, making light sheet microscopes compatible with all common microscope slides and dishes, the impact of which is enormous.

It is difficult to over-emphasise the importance of low-light illumination in fluorescence microscopy - particularly for research projects that require long-term imaging of organoids and embryos. Researchers will finally be able to exploit the gentle imaging of light sheet microscopy in an unrestricted way, using multi-well plates, grids and slides to image an order of magnitude more specimens than before. Enabling low phototoxicity imaging of organoids and embryos will drastically improve success rates in imaging, reducing the total number of animals required, making this microscope an essential tool in achieving the 3Rs in research using animals. The ability to easily image many samples in long-term imaging experiments removes selection bias and increases sample numbers by a factor of ten, leading to greatly improved data driven biology. The inverted lattice light sheet microscope will complement our existing live imaging equipment portfolio, resulting in a unique live bioimaging facility with world-leading capabilities.

In this project we will install a novel inverted lattice light sheet microscope into the Cambridge Advanced Imaging Centre (CAIC) to enable low photo-toxicity imaging of cells, embryos and organoids. The technical team in CAIC has extensive experience in light sheet microscopy, particularly in data management and analysis of the often many 100s GB generated per experiment. The inverted lattice light sheet microscope differs from CAIC's custom designed upright light sheet microscope in its novel ability to image glass slides, petri dishes and multi-well plates from beneath without loss of resolution. It does this by use of a dedicated dual lens system that share a common lens element before the coverslip interface. This allows the excitation and emission paths to propagate unimpeded through their respective illumination and collection paths. Adaptive optics in the microscope maintain a sharp focus of light sheet as it scans through samples at rates of 3 volumes per second. Altogether this enables low-phototoxicity fast 3D imaging in a easy to mount sterile environment.

The applications team will utilise this microscope and work with the staff scientists in CAIC to study: re-implantation embryonic development (Mouse and Human Embryos); growth and development of cells in 3D gel microenvironments; cell fate decisions and differentiation in human lung development and interactions between metabolic and developmental signalling networks in embryonic organoids.