Quantitative Phase-Contrast Imaging for Distinction between Different States of Human Breast Cancer Cells

Abstract

We present label-free phase imaging to differentiate human breast cancer cells for breast cancer diagnosis. Low-coherent quantitative phase microscopy (QPM) is exploited to provide speckle-free interference images of live cells adhered to a plate, from which the phase information of the individual cells can be extracted. The phase measurement performance of QPM is validated by the phase-derived optical thickness of a sub-wavelength featured sample, consistent with the results when using conventional atomic force microscopy (AFM). The phase sensitivity is recorded as ~44 mrad, corresponding to ~2.3 nm depth fluctuation during measurement. Phase-contrast imaging is performed with three breast epithelial cell lines: non-tumorous (MCF-10A), weakly malignant (MCF-7), and highly malignant (MDA-MB-231), which mimic an in vivo environments in development of human breast cancer. Our results indicate that MCF-10A and MDA-MB-231 exhibited significantly lower phase-shifts than those of MCF-7, but no difference in phase was observed between MCF-10A and MDA-MB-231. We expect that the use of the QPM approach would be beneficial for clinicians to quantitatively evaluate the breast cancer states from the unmodified specimen of breast biopsy.