Fig. 1.

A scheme of the cell and nucleus shape model: $n_n$,$n_c$ and $n_m$ are the RIs of the nucleus, cytoplasm and medium, respectively. $R_{1,n}$ and $R_{2,n}$ are the radii in the x-y projection cast by the nucleus, and $R_{3,n}$ is the radius of the nucleus in the z dimension; $R_{1,c}$ and $R_{2,c}$ are the radii in the x-y projection cast by the entire cell, and $R_{3,c}$ is the radius of the entire cell in the z dimension. The radii in the x-y projection are extracted from the OPD image and fluorescence image for the cytoplasm and the nucleus, respectively, and the radius in the z dimension is estimated to be their average. (a) Nucleus modeled as a tilted ellipsoid. (b) Nucleus modeled as an ellipsoid with main axes aligned with Cartesian coordinates, with identical $R_{1,n},R_{2,n},R_{3,n}$. The red and blue circles denote the center of mass of the cytoplasm and nucleus, respectively. The Cartesian coordinate system indicates directions, where light propagates in the z direction.