A hydrodynamic microchip for formation of continuous cell chains

Here, we demonstrate the unique features of a hydrodynamic based microchip for creating
continuous chains of model yeast cells. The system consists of a disk shaped microfluidic structure,
containing narrow orifices that connect the main channel to an array of spoke channels. Negative
pressure provided by a syringe pump draws fluid from the main channel through the narrow
orifices. After cleaning process, a thin layer of water is left between the glass substrate and the
polydimethylsiloxane microchip, enabling leakage beneath the channel walls. A mechanical clamp
is used to adjust the operation of the microchip. Relaxing the clamp allows leakage of liquid
beneath the walls in a controllable fashion, leading to formation of a long cell chain evenly
distributed along the channel wall. The unique features of the microchip are demonstrated by
creating long chains of yeast cells and model 15 μm polystyrene particles along the side wall and
analysing the hydrogen peroxide induced death of patterned cells.