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Updated: Dec 31, 2025
Lens-free Video Microscopy for the Dynamic and Quantitative Analysis of Adherent Cell Culture
Published on: February 23, 2018
One-shot phase-recovery using a cellphone RGB camera on a Jamin-Lebedeff microscope
Benedict Diederich1,2, Barbora Marsikova1,2, Brad Amos3
1Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745 Jena, Germany.
Abstract:
Jamin-Lebedeff (JL) polarization interference microscopy is a classical method for determining the change in the optical path of transparent tissues. Whilst a differential interference contrast (DIC) microscopy interferes an image with itself shifted by half a point spread function, the shear between the object and reference image in a JL-microscope is about half the field of view. The optical path difference (OPD) between the sample and reference region (assumed to be empty) is encoded into a color by white-light interference. From a color-table, the Michel-Levy chart, the OPD can be deduced. In cytology JL-imaging can be used as a way to determine the OPD which closely corresponds to the dry mass per area of cells in a single image. Like in other interference microscopy methods (e.g. holography), we present a phase retrieval method relying on single-shot measurements only, thus allowing real-time quantitative phase measurements. This is achieved by adding several customized 3D-printed parts (e.g. rotational polarization-filter holders) and a modern cellphone with an RGB-camera to the Jamin-Lebedeff setup, thus bringing an old microscope back to life. The algorithm is calibrated using a reference image of a known phase object (e.g. optical fiber). A gradient-descent based inverse problem generates an inverse look-up-table (LUT) which is used to convert the measured RGB signal of a phase-sample into an OPD. To account for possible ambiguities in the phase-map or phase-unwrapping artifacts we introduce a total-variation based regularization. We present results from fixed and living biological samples as well as reference samples for comparison.
Insights
This study revives Jamin-Lebedeff (JL) polarization interference microscopy for real-time optical path difference (OPD) measurements. By integrating 3D-printed components and a cellphone, it enables quantitative phase imaging of transparent tissues and cells.
Area of Science:
- Biophysics
- Optical Microscopy
- Image Processing
Background:
- Jamin-Lebedeff (JL) polarization interference microscopy is a classical technique for measuring optical path differences (OPD) in transparent samples.
- Traditional JL microscopy uses a Michel-Levy chart for OPD deduction, limiting real-time analysis.
- Quantitative phase measurements are crucial in cytology for determining dry mass per area of cells.
Purpose of the Study:
- To develop a real-time quantitative phase measurement method using Jamin-Lebedeff microscopy.
- To modernize the JL setup with 3D-printed parts and a cellphone for enhanced functionality.
- To enable accurate OPD determination in biological samples, including living cells.
Main Methods:
- Implemented a single-shot phase retrieval algorithm for real-time measurements.
- Integrated 3D-printed components and a cellphone RGB-camera into the JL microscope setup.
- Developed a gradient-descent based inverse problem with total-variation regularization for accurate phase mapping and unwrapping.
Main Results:
- Successfully adapted a classical Jamin-Lebedeff microscope for real-time quantitative phase measurements.
- Demonstrated the method's efficacy on fixed and living biological samples, as well as reference objects.
- Achieved accurate optical path difference (OPD) mapping, correlating with dry mass per area in cells.
Conclusions:
- The modernized JL microscopy enables rapid, quantitative phase imaging of transparent samples.
- The developed phase retrieval algorithm overcomes limitations of traditional methods, allowing real-time analysis.
- This approach provides a cost-effective and accessible tool for quantitative phase imaging in various biological applications.
