High-speed production and dispensing of enucleated oocyte by microrobot on a chip

We present an enucleation process with ejection module of bovine oocytes on a microfluidic chip to achieve the high speed enucleation of the oocytes and ejection of enucleated oocyte to the culture environment. By combining microfluidic chip and micororobotics, the flow in a channel can be actively controlled and we achieved successive operations of 1) loading oocyte, 2) control cutting volume and 3) removing nucleus, 4) dispensing enucleated oocyte immediately. After enucleation process, enucleated oocyte could be ejected to the culture well immediately, and ejected oocytes are neatly arranged in the culture array, this shows great ease of single oocyte operation. The magnetically actuated microrobot can control local fluid flow by changing its position like gate valve and control fluid force distributions in a microchip which govern oocyte movement in a chip. The optimally designed microchannel for enucleation enables continuous operation and cutting bovine oocyte with smooth manner by hydrodynamic force. Removed nucleus is thrown away from withdrawal microchannel, however the remaining part of oocyte dispensed from the nozzle hole is collected by a culture array.