Orientation control of single cells in microfluidic channel

Abstract

Single cell manipulation technology has been instrumental in the development of Assisted Reproductive Technologies (ARTs) for clinical and research applications. In-vitro fertilization of gametes and embryos have now become a routine procedure to treat infertility problems in clinics. However, the success rate of these procedures remains very low due to the inefficiency involved with manual manipulation of microtools by human operator, resulting in low throughput, low repeatability and interoperator variability. In particular, controlling the polar body orientation of cells as required prior to micropipette injection remains a challenging task to perform manually by repeated release and aspiration of cells. The current study investigates the use of a microfluidic platform to automate the process of cell positioning, immobilization and orientation control by means of hydrodyanmic force and vision-based position control with the aim of increasing the efficiency of micromanipulation. The device is accessible by a conventional micropiette via a cavity, allowing immobilized cells to be processed for tasks such as microinjection and selective biopsy. An iterative orientation control algorithm based on the dynamics of cell movement within microchannel is proposed. Visual tracking of polar body is used to provide orientation information of cells. Experimental results with mouse embryos indicate that cell orientation can be systematically controlled autonomously without human intervention and provides a framework for further development of robotics approach to precise manipulation of microparticles within microfluidic devices.