A smart scanning microscope for better observations of cell sheets

Details

Published on 11 November 2021

Modern biology is based on the observation of living cells, made possible within model organisms by the latest advances in optical microscopy. The widely used confocal fluorescence microscope generates volumetric images with high spatial resolutions, by scanning the volume point by point with a laser beam. However, current techniques are confronted with a problem of toxicity due to the illumination necessary for the excitation of fluorescent markings: prolonged illumination affects and slows down the growth of cells. Nevertheless in many situations, in particular in the case of embryos and developing tissues, cells are organized along sheets lying on curved surfaces. Conventionally, such objects are imaged by scanning the entire volume plane by plane, which is highly inefficient in terms of photon budget.

A team of researchers at Institut Fresnel in Marseille developed a new microscope that automatically estimates the surface on which these cells are distributed from a small number of random acquisitions (~0.1% of the voxels). The microscope can then concentrate the illumination around the surface of interest, allowing cell sheets imaging by scanning typically less than 5% of the volume. Additionally, it can also restrict illumination along the fluorescent cell contours by alternating acquisitions and prediction steps, further reducing the scanned volume up to 1%. The corresponding reduction in light dose on the sample had a profound effect on fluorophore stability and will improve viability of living samples over prolonged imaging.

F. Abouakil, H. Meng, M. A. Burcklen, H. Rigneault, F. Galland, and L. LeGoff, “An adaptive microscope for the imaging of biological surfaces,” Light Sci. Appl. 10, 210 (2021).
https://doi.org/10.1038/s41377-021-00649-9