Single-cell diffraction tomography with optofluidic rotation about a tilted axis

TL;DR

This paper introduces a method for 3D refractive index imaging of single cells using optical diffraction tomography with optofluidic rotation about a tilted axis, improving reconstruction accuracy.

Contribution

It presents a novel approach to account for tilted rotational axes in single-cell diffraction tomography, enhancing 3D image reconstruction.

Findings

Improved 3D reconstructions by considering tilted axes.

Successful application to biological cells in microfluidic devices.

Enhanced accuracy over traditional methods.

Abstract

Optical diffraction tomography (ODT) is a tomographic technique that can be used to measure the three-dimensional (3D) refractive index distribution within living cells without the requirement of any marker. In principle, ODT can be regarded as a generalization of optical projection tomography which is equivalent to computerized tomography (CT). Both optical tomographic techniques require projection-phase images of cells measured at multiple angles. However, the reconstruction of the 3D refractive index distribution post-measurement differs for the two techniques. It is known that ODT yields better results than projection tomography, because it takes into account diffraction of the imaging light due to the refractive index structure of the sample. Here, we apply ODT to biological cells in a microfluidic chip which combines optical trapping and microfluidic flow to achieve an optofluidic single-cell rotation. In particular, we address the problem that arises when the trapped cell is not rotating about an axis perpendicular to the imaging plane, but instead about an arbitrarily tilted axis. In this paper we show that the 3D reconstruction can be improved by taking into account such a tilted rotational axis in the reconstruction process.