Single-shot quantitative phase imaging as an extension of differential interference contrast microscopy

Various studies have been conducted to obtain quantitative phase information based on differential interference contrast (DIC) microscopy. As one such attempt, we propose in this study a single-shot quantitative phase imaging (QPI) method by combining two developments. First, an add-on optical system to a commercialized DIC microscope was developed to perform quantitative phase gradient imaging (QPGI) with single image acquisition using a polarization camera. Second, an algorithm was formulated to reconstitute QPI from the obtained QPGI by reducing linear artifacts, which arise in simply integrated QPGI images. To demonstrate the applicability of the developed system in cell biology, the system was used to measure various cell lines and compared with fluorescence microscopy images of the same field of view. Consistent with previous studies, nucleoli and lipid droplets can be imaged by the system with greater optical path lengths (OPL). The results also implied that combining fluorescence microscopy and the developed system might be more informative for cell biology research than using these methods individually. Exploiting the single-shot performance of the developed system, time-lapse imaging was also conducted to visualize the dynamics of intracellular granules in monocyte-/macrophage-like cells. Our proposed approach may accelerate the implementation of QPI in standard biomedical laboratories.

Automated summary

A single-shot quantitative phase imaging (QPI) method was proposed by combining DIC microscopy and QPI in this study. The system successfully imaged nucleoli and lipid droplets in cell biology research, and combining it with fluorescence microscopy may provide more comprehensive information for research. Time-lapse imaging was also conducted to visualize the dynamics of intracellular granules in monocyte-/macrophage-like cells, demonstrating the potential of this approach for standard biomedical laboratories.