This paper reports the development of APRIL, an automated robotic system for embryo culture dish preparation. The research team, based on a commercial liquid handling platform, achieved precise distribution of culture medium through custom adapters and control algorithms, thereby improving operational consistency and efficiency, and completed a full-process study from technical development to preliminary clinical validation. Automating some routine repetitive operations in assisted reproductive laboratories has long been a goal of many research teams and companies. Although the product discussed in this paper may not represent the final form, its pioneering achievements and research methods provide valuable experience and references for subsequent related work. Currently, the system still has certain limitations, such as being only compatible with specific models of culture dishes and requiring manual supervision for some operational steps. Overall, this study provides a feasible path for automating IVF laboratories, and its clinical application effects need to be further verified in larger-scale studies.
Research Background
The success of in vitro fertilization (IVF) highly depends on precise control of the embryo culture environment, and the preparation of culture dishes is a crucial link. Traditional manual preparation methods are not only time-consuming and labor-intensive but also prone to fluctuations in key parameters such as droplet volume and pH due to inter-operator variability or fatigue, which in turn affect embryo development. With the growing global demand for assisted reproduction and the intensification of embryologist shortages, laboratories are in urgent need of solutions that can improve efficiency and reduce human errors. This study developed and validated an automated liquid handling robot named ART Pipetting Robot for the IVF Laboratory (APRIL), aiming to optimize the preparation process of embryo culture dishes through standardized operations, providing more stable and efficient technical support for IVF laboratories.
Research Methods
APRIL is based on the Opentrons OT-2 liquid handling robot platform, enabling high-precision operation of microdroplet culture dishes through custom 3D-printed adapters. The system is equipped with two robotic arms: one uses a P300 single-channel pipette to dispense 25 µL of embryo culture medium, and the other uses a P1000 single-channel pipette to cover 5 mL of mineral oil. To ensure safety, all contact materials have passed the mouse embryo assay (MEA) for toxicity, and a high-efficiency air filtration module is installed to maintain a clean internal environment. The study adopted a prospective randomized controlled design to compare the performance of APRIL-prepared and manually prepared culture dishes in terms of droplet quality, pH stability, and embryo development rate. For droplet quality, weighing data from 30 robot-prepared and 90 manually prepared culture dishes were analyzed, and the coefficient of variation (CV) was calculated to assess consistency. For pH testing, the pH changes of culture dishes in the robot group and manual group after overnight culture were compared. Embryo development assessment included the blastocyst formation rate of mouse embryos and the development of human embryos on day 3 and day 5, to comprehensively verify the reliability and clinical applicability of the automated system.
Research Results
APRIL showed outstanding performance in droplet preparation precision, with a coefficient of variation of only 0.46% for droplet mass, far lower than the 6%–7% of manual preparation, indicating high consistency. pH testing showed that the pH of culture dishes prepared by the robot remained between 7.281 and 7.33, comparable to the 7.275–7.311 of manually prepared ones, both within the ideal range for embryo culture. In mouse embryo experiments, the blastocyst formation rate in the APRIL group reached 100%, slightly higher than the 90%–91% in the manual group. Data on human embryo culture showed that the day 3 embryo development rate in the robot group was significantly higher (92.4% vs. 82.6%), and the day 5 blastocyst rate (19.75% vs. 15.57%) and total number of usable embryos (50.3% vs. 46.1%) also increased, though the latter two differences did not reach statistical significance. These results indicate that the automated system can provide a more stable culture environment and may have a positive impact on embryo development.
Research Innovations
The innovations of APRIL mainly lie in technical design and application safety. Technically, the system is the first to apply automated liquid handling technology to the preparation of human IVF culture dishes. Through custom 3D-printed adapters and optimized control algorithms (such as dynamically adjusting pipetting depth to avoid bubble formation), it achieves far higher precision and repeatability than manual operations. In terms of safety, all contact materials of APRIL have passed rigorous embryo toxicity testing, and its operation process does not directly involve human gametes or embryos, reducing the risk of contamination or damage. In addition, the system can handle 20 culture dishes at a time, significantly improving laboratory efficiency, saving valuable time for embryologists, and allowing them to focus on other key steps that require more manual intervention.
Research Limitations
Despite its many advantages, APRIL has certain limitations. First, the system is currently only compatible with a specific model of culture dish (Vitrolife 16003). If laboratories use dishes from other brands, adapters and control codes need to be redesigned and adjusted, which limits its universality. Second, although APRIL can independently complete most operations, manual supervision is still required to ensure correct loading of consumables (such as culture medium, mineral oil, and pipette tips), and full automation has not yet been achieved. Furthermore, the sample size of human embryo research is relatively small (324 embryos), and some results (such as the day 5 blastocyst rate) did not reach statistical significance. Larger-scale clinical studies are needed in the future to further verify its long-term benefits.
Clinical Significance and Prospects
The introduction of APRIL provides IVF laboratories with a standardized and reproducible culture dish preparation protocol. Its high precision and stability are expected to improve the embryo culture environment, thereby enhancing clinical pregnancy rates. Especially for high-throughput laboratories, automated technology can significantly reduce the workload of embryologists, minimize batch-to-batch variations caused by human errors, and may reduce additional treatment costs due to improper operations. Although its current functions are limited, the successful validation of APRIL lays a foundation for expanding automated technology to other key IVF steps (such as sperm injection or embryo transfer) in the future. Moreover, against the backdrop of global embryologist shortages, the promotion of such technologies helps alleviate the strain on human resources, providing timely and efficient treatment options for more infertile patients.
reference
Lattin MT, Djandji AS, Kronfeld MT, Samsel T, Ling R, Ciskanik M, Sadowy S, Forman EJ, Williams Z. Development and validation of an automated robotic system for preparation of embryo culture dishes. Fertil Steril. 2024 Aug;122(2):297-303. doi: 10.1016/j.fertnstert.2024.04.016. Epub 2024 Apr 15. PMID: 38631505.