We have developed a novel technique for fluorescent monitoring of a bovine oocyte nucleus for an automatic cloning device. Animal cells that have been chemically softened by cytochalasin and stained with Hoechst dye are aspirated into a thin microchannel of a microfluidic chip and stretched thin, allowing the nucleus of the expanded oocyte to be monitored. Half the volume of the oocyte is aspirated into the thin microchannel and a high-velocity fluid flow is generated in the wide microchannel to bisect the oocyte. Then, the half-oocytes are monitored to determine which contains the nucleus. To control flow velocity with high accuracy and rapid response, we also developed a syringe pump that is small, has no backlash, and has highly-accurate volume control and a good response for automatic cutting. In this report, we describe the monitoring method and construction of the syringe pump.

We have developed a novel technique for injecting and cutting animal cells for an automatic cloning system. Animal cells that have been chemically softened are aspirated into a narrow teflon tube, which is then inserted into a microfluidic chip. The tube's tip is inserted into a microchannel and releases the aspirated cells in the microchannel. The microfluidic chip contains two orthogonal channels. One is a narrow microchannel that aspirates and fixes a cell; in the other channel, a fluid flows at high velocity for cutting the aspirated cell. The thickness of the aspiration channel can be adjusted to fix the aspirated cell. Half the volume of the cell is aspirated into the narrow microchannel and high-speed flow is then generated to cut the cell into two. In this report, the cutting method and the injection method are described. Then an imaging process is also investigated for an automatic cutting.