Tomographic flow cytometry by digital holography.

Area of Science:

• Biophotonics
• Cellular Imaging
• Microfluidics

Background:

• High-throughput single-cell analysis is crucial but technically demanding.
• Label-free tomographic phase microscopy offers a promising, non-invasive approach.
• Current in-line tomography methods require complex sample manipulation (rotation, multi-directional probing).

Purpose of the Study:

• To develop a simplified, practical in-line phase-contrast tomography method for continuous-flow single-cell analysis.
• To eliminate the need for mechanical sample rotation and complex optical setups.
• To demonstrate the method's versatility across different cell types.

Main Methods:

• Exploiting random cell rolling within a microfluidic channel.
• Implementing advanced wavefront analysis strategies using digital holography.
• Retrieving 3D cell position and orientation numerically without prior knowledge.
• Applying two alternate wavefront analysis strategies for diverse biosamples.

Main Results:

• Successful implementation of in-line phase-contrast tomography without sample rotation.
• Accurate characterization of disparate cell types (red blood cells, diatoms).
• Demonstrated retrieval of 3D cell information through numerical wavefront analysis.
• Significant simplification of the optical system for practical cytotomography.

Conclusions:

• The proposed method enables practical, continuous-flow cytotomography for high-throughput single-cell analysis.
• Random cell rolling combined with digital holography circumvents complex mechanical requirements.
• The approach is versatile and adaptable for analyzing various biological samples.