Spectral domain phase microscopy: A new tool for measuring cellular dynamics and cytoplasmic flow

摘要

Broadband interferometry is an attractive technique for the detection of cellular motions because it provides depthresolvedinterferometric phase information via coherence gating. Here a phase sensitive technique called spectraldomain phase microscopy (SDPM) is presented. SDPM is a functional extension of spectral domain optical coherencetomography that allows for the detection of cellular motions and dynamics with nanometer-scale sensitivity. Thissensitivity is made possible by the inherent phase stability of spectral domain OCT combined with common-pathinterferometry. The theory that underlies this technique is presented, the sensitivity of the technique is demonstrated bythe measurement of the thermal expansion coefficient of borosilicate glass, and the response of an Amoeba proteus topuncture of its cell membrane is measured. We also exploit the phase stability of SDPM to perform Doppler flowimaging of cytoplasmic streaming in A. proteus. We show reversal of cytoplasmic flow in response to stimuli, and weshow that the cytoplasmic flow is laminar (i.e. parabolic) in nature. We are currently investigating the use of SDPM in avariety of different cell types.