We report a microscopic approach for determining cell cycle stages by measuring the nuclear optical path length
(OPL) with quantitative differential interference contrast (DIC) microscopy. The approach is validated by the
excellent agreement between the proportion of proliferating-to-quiescent cancerous breast epithelial cells obtained
from DIC microscopy, and that from a standard immunofluorescence assay.
Clinical tissue processing such as formalin fixing, paraffin-embedding and histological staining alters significantly the
optical properties of the tissue. We document the alterations in the optical properties of prostate cancer tissue specimens in the 500nm to 700nm spectral range caused by histological processing with quantitative differential interference contrast (qDIC) microscopy. A simple model to explain these alterations is presented at the end.
We report here a new approach based on an extension of the transport of the intensity equation for three dimensional refractive index imaging of a weak phase object from a series of images recorded by a differential interference contrast microscope at different focus (z-stack). Our method is first validated by imaging polystyrene spheres. We then apply this method to monitor in vivo apoptosis of human breast MCF7 epithelial cells. The potential applications are discussed at the end.