Observation of cell pinball through high speed switching between reflection interference and phase contrast

“Cell Pinball” is a phenomenon whereby rotating red blood cells (RBCs) move like pinballs inside a microfluidic channel where the cell inertia is negligible. The goal of this paper is to discuss the location of the actual rotational axis through the careful comparison between the contour and contact shapes of a moving RBC. By switching the reflection interference contrast (RIC) and the phase contrast (PhC) microscopes with the mean cycle time of 0.440 s, we found that the difference between the trajectories of each centroid of the visualized RBC by RIC and PhC is less than 0.8 μm.