Characterizing cellular contractility and cytoplasmic flow using spectral domain phase microscopy

The phase information inherent to spectral domain optical coherence tomography (OCT) processing can be exploited to resolve sub-coherence length displacement variations. Spectral domain phase microscopy (SDPM) is a functional extension of Fourier domain OCT whose common-path topology enables extraordinary phase sensitivity. Here we demonstrate the usefulness of SDPM in three biologically relevant applications: real-time tracking of cell surface displacements of contracting cardiac myocytes, extracting cytoplasmic flow characteristics for a single-celled organism (flow rates similar to 10-30 mu m/s), and cellular mechanical responses to cytoskeletal drug treatments. The results of these experiments are corroborated by light microscopy acquired concurrently with the SDPM data.