Quantitative dynamic cellular imaging based on 3D unwrapped optically computed phase microscopy.

Abstract

We investigate continuous observation of dynamic phenomena through quantitative phase microscopy. We conduct imaging studies using optically computed phase microscopy, a novel imaging technology developed in our lab, to the best of our knowledge. Inevitably, continuous phase imaging is affected by phase wrapping artifacts, which affects correct quantification of sample dynamics. To address this issue, we develop a 3D unwrapping method that exploits data correlation in space as well as in time. We validate our 3D phase unwrapping method using simulated data. We further validate 3D phase unwrapping using experimental data and demonstrate quantitative phase imaging that accurately characterizes sample dynamics. We image the nanoscale motion of the sample actuated by a piezo transducer (PZT). We calculate the displacement using 3D unwrapped phase, and the result is consistent with the known motion of the PZT. We also image live cells that were detaching from the substrate of the petri dish. The optical path length calculated using 3D unwrapped phase increases as the dry mass of the cell becomes more concentrated during the detachment process.