From teleoperated to automatic blastocyst microinjections: Designing a new system from expert-controlled operations

Blastocyst microinjections are routinely involved in the process of creating genetically modified mice for biomedical research, but their efficiency is typically poor and highly dependent on the skills of the operators. Here, the goal of increasing the consistency and efficiency rates of these operations was pursued through robotics and automation. Initially, a teleoperated microinjection system was designed and implemented. Then, this system was evaluated under the control of a microinjection expert. The evaluation consisted of a series of blastocyst microinjections, which are presented and analyzed in this paper. The knowledge gained from these experiments was then used to: 1) create a new system setup more appropriate for automating consecutive blastocyst microinjections; 2) derive rules to guide automatic microinjections; and 3) define future research directions and system upgrades to further increase the system performance. Finally, experiments with the encoded algorithm for automatic blastocyst microinjections attested the validity of the derived rules by demonstrating a 75% success rate. The good quality of the microinjections was demonstrated by the 53% birth rate and the 20% yield of chimeras obtained from the implanted blastocysts.