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Related Experiment Video

Updated: Jan 21, 2026

Label-Free Identification of Lymphocyte Subtypes Using Three-Dimensional Quantitative Phase Imaging and Machine Learning

Label-Free Identification of Lymphocyte Subtypes Using Three-Dimensional Quantitative Phase Imaging and Machine Learning

Published on: November 19, 2018

Epi-mode tomographic quantitative phase imaging in thick scattering samples.

Patrick Ledwig¹, Francisco E Robles¹

¹Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA.

Biomedical Optics Express

|July 31, 2019

Summary

This summary is machine-generated.

Quantitative phase imaging (QPI) now analyzes thick, scattering biological samples. This breakthrough uses epi-illumination and deconvolution to reveal sub-cellular details non-invasively and without labels.

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Area of Science:

Biomedical Optics
Cellular Imaging
Microscopy

Background:

Quantitative Phase Imaging (QPI) enables label-free, nanoscale imaging of live cells and transparent samples.
Current QPI methods are limited to thin specimens, restricting their biomedical applications.
Thick, scattering biological tissues are challenging for conventional QPI.

Purpose of the Study:

To overcome the limitation of sample thickness in QPI.
To enable quantitative phase imaging in thick, scattering biological samples.
To develop a flexible QPI configuration for non-invasive, label-free imaging.

Main Methods:

Epi-mode illumination configuration.
Utilizing multiple scattering within the sample as transmissive illumination.
Phase quantification via deconvolution by modeling the system's transfer function.
Ensemble average angular distribution of light at the focal plane.

Main Results:

Successfully enabled quantitative phase imaging in thick, scattering samples.
Demonstrated label-free, real-time sub-cellular imaging capabilities.
Validated the technique on phantoms, blood, organoids, and whole mouse brains.

Conclusions:

Developed a novel QPI technique for thick, scattering specimens.
This method enhances QPI's versatility for non-invasive biomedical research.
Opens possibilities for label-free, tomographic imaging of unaltered biological tissues.