Intact entrapment of floating cells and particles on chip by streamline manipulation for single-cell analysis

Here a procedure for intact entrapment of single cells by a microfluidic chip is modeled and described. This chip consists of multiple inlets and outlets. Two inlets were used for focusing cells on a side wall toward the main outlet. Microchannels perpendicular to the main channel were applied to absorb and trap focused cells while applied pressure on captured cells was kept as low as possible in order to preserve cells vital features for further experiments. Equivalent electrical circuit model for microchannel network study revealed that extra hydrodynamic resistance in the main channel outlet is necessary for effective cells entrapment. A third inlet near the outlet was used in this regard with the same width to the main channel approximately. Moreover, a Porous barrier in the side channel prevented a high pressure drop over isolated cells. Finite Element Method study of microchannel network disclosed high entrapment efficiency of the proposed structure. The particles with the diameter between 15 μm and 25 μm, which are the typically known as the diameter for CTCs, can be easily separated from other ones. In addition, the difference between upstream and downstream pressures dwindles by more than 90%, while the velocity in the main channel was 0.1 m/s.

Keywords:

Microfluidics , Circulating Tumor Cells , Hydrodynamic Resistance , microchannel