Figure 1. Sketch of the experimental setup.

Cells, e.g. cell (i) and (ii), grew in a microfluidic device consisting of dead-end growth channels that were connected at their open end to a large main channel. If cell division is blocked, the cells grow as filaments that penetrate into the main channel. A fluid flow with velocity and a profile similar to the one depicted created a hydrodynamic force that deformed the cells, as is shown for cell (ii). The magnitude of the force was controlled by the infusion rate. For analysis, the arc length () was measured from the point of connection between the growth channels and the main channel () to the tip of the cell (). To characterize the shape of the cell, the angle profile () was calculated (see Materials and Methods).