Domes and semi-capsules as model systems for infrared microspectroscopy of biological cells.

Solheim, JH; Brandsrud, MA; Kong, B; Banyasz, A; Borondics, F; Micouin, G; Lossius, S; Sule-Suso, J; Blümel, R; Kohler, A

Abstract

It is well known that infrared microscopy of micrometer sized samples suffers from strong scattering distortions, attributed to Mie scattering. The state-of-the-art preprocessing technique for modelling and removing Mie scattering features from infrared absorbance spectra of biological samples is built on a meta model for perfect spheres. However, non-spherical cell shapes are the norm rather than the exception, and it is therefore highly relevant to evaluate the validity of this preprocessing technique for deformed spherical systems. Addressing these cases, we investigate both numerically and experimentally the absorbance spectra of 3D-printed individual domes, rows of up to five domes, two domes with varying distance, and semi-capsules of varying lengths as model systems of deformed individual cells and small cell clusters. We find that coupling effects between individual domes are small, corroborating previous related literature results for spheres. Further, we point out and illustrate with examples that, while optical reciprocity guarantees the same extinction efficiency for top vs. bottom illumination, a scatterer's internal field may be vastly different in these two situations. Finally, we demonstrate that the ME-EMSC model for preprocessing infrared spectra from spherical biological systems is valid also for deformed spherical systems.

Citation

Solheim, J., Brandsrud, M., Kong, B., Banyasz, A., Borondics, F., Micouin, G., …Kohler, A. (2023). Domes and semi-capsules as model systems for infrared microspectroscopy of biological cells. Scientific reports, 13(1), Article 3165. https://doi.org/10.1038/s41598-023-30130-z

• Journal Article Type: Article
• Acceptance Date: Feb 16, 2023
• Publication Date: Feb 23, 2023
• Journal: Scientific Reports
• Print ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 1
• Article Number: 3165
• DOI: https://doi.org/10.1038/s41598-023-30130-z
• Publisher URL: https://www.nature.com/articles/s41598-023-30130-z