Label-free cell-based assay with spectral-domain optical coherence phase microscopy

Area of Science:

• Biophotonics and Imaging
• Cellular Dynamics and Physiology
• Label-Free Biosensing

Background:

• Quantitative measurement of unstained living cell dynamics is crucial for cellular function studies and drug discovery.
• Conventional label-free optical methods often require specialized nanostructure-patterned substrates to examine cellular responses to stimuli.
• There is a need for advanced optical platforms that enable label-free, quantitative analysis of cell dynamics without complex substrate requirements.

Purpose of the Study:

• To introduce and validate spectral-domain optical coherence phase microscopy (SD-OCPM) as a quantitative imaging method for label-free cell-based assays.
• To demonstrate the capability of SD-OCPM in measuring dynamic cellular responses.
• To assess the utility of SD-OCPM for investigating cellular reactions to specific chemical stimuli.

Main Methods:

• Development and implementation of a spectral-domain optical coherence phase microscopy (SD-OCPM) instrument.
• The SD-OCPM utilizes low-coherence interferometry for quantitative, depth-resolved phase measurements of transparent specimens.
• High phase stability was achieved for precise measurements of cellular dynamics.

Main Results:

• SD-OCPM successfully performed quantitative imaging of dynamic cellular responses in unstained living cells.
• The study demonstrated the measurement of dynamic responses in human breast cancer cells (MCF-7).
• Cellular responses to 2-picolinic acid (PA) and histamine were quantitatively assessed using SD-OCPM.

Conclusions:

• SD-OCPM is presented as a viable and powerful optical platform for label-free cell-based assays.
• The method enables quantitative, depth-resolved phase measurements, offering high phase stability for dynamic cellular analysis.
• SD-OCPM advances the field by providing a substrate-independent approach for studying cellular dynamics and facilitating drug discovery.