Stain-free quantification of chromosomes in live cells using regularized tomographic phase microscopy

Area of Science:

• Biophysics
• Cell Biology
• Optical Imaging

Background:

• Refractive index imaging offers label-free, minimally perturbing monitoring of live cell structures.
• Existing tomographic methods suffer from limited 3D resolution and artifacts, hindering accurate quantification.
• There is a need for advanced techniques to achieve high-resolution, quantitative refractive index imaging in native cellular environments.

Purpose of the Study:

• To develop a regularized tomographic phase microscope (RTPM) for accurate 3D refractive index imaging of intracellular components.
• To overcome limitations of existing methods, enabling precise quantification within intact, live cells.
• To demonstrate the application of RTPM for cellular mass analysis and differentiation.

Main Methods:

• Development of a regularized tomographic phase microscope (RTPM).
• Application of RTPM for high-resolution, quantitative refractive index imaging of organelles within intact cells.
• Utilizing dual-wavelength RTPM for enhanced molecular composition analysis.

Main Results:

• Achieved accurate 3D refractive index imaging of organelles in live cells.
• Successfully quantified the non-aqueous (dry) mass of chromosomes in intact living cells.
• Differentiated between HT-29 and T84 human colon cancer cell lines based on chromosome dry mass.
• Demonstrated potential for determining molecular composition of cellular organelles using dual-wavelength RTPM.

Conclusions:

• RTPM provides accurate, label-free 3D refractive index imaging for live cell analysis.
• The technique enables precise quantification of cellular components, such as chromosome mass.
• RTPM shows promise for distinguishing cell types and analyzing molecular composition in live cells.