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bioRxiv · 10.1101/2021.10.01.462719

Characterization of Cell-Induced Astigmatism in High-Resolution Imaging.

Rodrigues de Mercado, R.·van Hoorn, H.·de Valois, M.·Backendorf, C.·Eckert, J.·Schmidt, T.
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Abstract

High-resolution and super-resolution techniques become more frequently used in thick, inhomogeneous samples. In particular for imaging life cells and tissue in which one wishes to observe a biological process at minimal interference and in the natural environment, sample inhomogeneities are unavoidable. Yet sample-inhomogeneities are paralleled by refractive index variations, for example between the cell organelles and the surrounding medium, that will result in the refraction of light, and therefore lead to sample-induced astigmatism. Astigmatism in turn will result in positional inaccuracies of observations that are at the heart of all super-resolution techniques. Here we introduce a simple model and define a figure-of-merit that allows one to quickly assess the importance of astigmatism for a given experimental setting. We found that astigmatism caused by the cells nucleus can easily lead to aberrations up to hundreds of nanometers, well beyond the accuracy of all super-resolution techniques. The astigmatism generated by small objects, like bacteria or vesicles, appear to be small enough to be of any significance in typical super-resolution experimentation.

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Rodrigues de Mercado, R., van Hoorn, H., de Valois, M., Backendorf, C., Eckert, J., Schmidt, T.. 2021-10-02. Characterization of Cell-Induced Astigmatism in High-Resolution Imaging.. https://doi.org/10.1101/2021.10.01.462719

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