Optical diffraction tomography for assessing single cell models in angular light scattering

Kaitlin J Dunn; Alex Matlock; George Funkenbusch; Zahid Yaqoob; Peter T C So; Andrew J Berger

doi:10.1364/BOE.512149

Optical diffraction tomography for assessing single cell models in angular light scattering

Biomed Opt Express. 2024 Jan 24;15(2):973-990. doi: 10.1364/BOE.512149. eCollection 2024 Feb 1.

Authors

Kaitlin J Dunn¹, Alex Matlock², George Funkenbusch³, Zahid Yaqoob^{2

4}, Peter T C So^{2

5}, Andrew J Berger¹

Affiliations

¹ The Institute of Optics, University of Rochester, Rochester, NY, USA.
² Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
³ Department of Biomedical Engineering, Duke University, Durham, NC, USA.
⁴ Department of Biomedical Engineering, Boston University, Boston, MA, USA.
⁵ Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.

Abstract

Angularly resolved light scattering (ALS) has become a useful tool for assessing the size and refractive index of biological scatterers at cellular and organelle length scales. Sizing organelle populations with ALS relies on Mie scattering theory models, which require significant assumptions about the object, including spherical scatterers and a homogeneous medium. These assumptions may incur greater error at the single cell level, where there are fewer scatterers to be averaged over. We investigate the validity of these assumptions using 3D refractive index (RI) tomograms measured via optical diffraction tomography (ODT). We compute the angular scattering on digitally manipulated tomograms with increasingly strong model assumptions, including RI-matched immersion media, homogeneous cytosol, and spherical organelles. We also compare the tomogram-computed angular scattering to experimental measurements of angular scattering from the same cells to ensure that the ODT-based approach accurately models angular scattering. We show that enforced RI-matching with the immersion medium and a homogeneous cytosol significantly affects the angular scattering intensity shape, suggesting that these assumptions can reduce the accuracy of size distribution estimates.