Semi-closed microchip for probe manipulation and the target cell harvesting

In this paper, we propose a semi-closed microchip which can realize the probe type manipulation in the microchip with the internal environment sealed off from the external environment. Long-term experiments can be conducted for in-situ culture and analysis of cells by the semi-closed microchip. The semi-closed microchip has a bath in the middle of microchannel to allow the insertion of micropipettes into the microchip. The bath is sealed off by thin oil film to prevent the evaporation of the solution in the bath. The seal by the oil film can maintain even if micropipettes are inserted into the bath and pulled out from the bath because the oil film can fill the hole by its surface tension. The seal by the oil film was evaluated by measuring the weight of the bath after 12/24 hours. To use the semi-closed microchip for cell culture and cell analysis, the exchange of the solution in the bath was demonstrated. It was also demonstrated that the cell fixation with the thermo sensitive gel in the proposed semi-closed microchip by fabricating the ITO electrodes as heaters in the bath. Cell culture and the target cell harvesting were conducted by the semi-closed microchip. The proposed semi-closed microchip can be used for cell culture, cell analysis and cell harvesting under a microscope as the biological applications for single cell analysis.