This work is the first demonstration of use of dynamic contrast in optical coherence tomography (OCT). Microscopic imaging of cellular motility has recently advanced from two dimensions to three dimensions for applications in drug

development. However, significant degradation in resolution occurs with increasing imaging depth, limiting access to motility information from deep inside the sample. Here, digital holographic optical coherence imaging is adapted to allow visualization of motility in tissue at depths inaccessible to conventional motility assay approaches. This method tracks the effect of cytoskeletal anti-cancer drugs on tissue inside its natural three-dimensional environment using time-course measurement of motility within tumor tissue.