Validation of a Novel High-Capacity Automated Incubator for In Vitro Fertilization (IVF)
Matia Algué et al., American Society for Reproductive Medicine (ASRM) 2025 Scientific Congress & Expo
Objective
To assess the stability of a high-capacity automated incubator through a series of tests including mouse embryo culture, pH stability under normal and stress conditions, osmolality variations, temperature stability during routine and stress conditions and volatile organic compound (VOC) levels.
Materials and Methods
The Cytomat™ 5C Series (ThermoFisher) is a high-capacity incubator designed to accommodate up to 105 standard dishes across 5 internal rotating vertical racks. It features an automated system that retrieves individual dishes through a small rear or side door and has a large standard front door for easy access to the incubator, in the event of a malfunction. To evaluate its performance after an out-gassing period of 6 weeks at 45ºC, fresh 1-cell stage hybrid (B6/CBAF1) mouse embryos (n=275) were cultured for 120 hours across all racks. A control group (n=75) was cultured under identical conditions in a benchtop incubator. Key developmental parameters - two-cell division, expanded blastocyst rate (EBR) on days 5 and 6, and good quality (GQ) blastocyst formation were assessed. On day 6, embryos were fixed and stained for total cell counts. pH and osmolality were measured using a blood gas analyzer (Siemens) and vapor pressure osmometer (Vapro 5600, Wescor), respectively. Temperature was monitored with Thermologgers (BirghtSentinel), and VOCs/formaldehydes (HCHO) were measured using a ppm-sensitive VOCmeter (VFM200, Extech Instruments). Statistical analysis was performed using Fisher’s or t-test.
Results
No significant differences (p>0.05) were observed between test and control groups in development parameters, including cleavage rate (100% vs. 100%), EBR on day 5 (96.4% vs. 97.3%), EBR on day 6 (97.8% vs. 97.3%), and GQ blastocysts (88.8% vs. 89.0%). Cell counts were also comparable (p>0.05) between the test (167.0±30.5) and the control group (178.0±23.8).
Average pH under standard conditions (6%CO2 and 5%O2) across 5 racks was 7.306. Following a cut-off power for 1 hour, pH at 0- and 2-hours post-restoration averaged 7.304 and 7.301, respectively.
Medium osmolality started (from the bottle) at 256.9 mOsm/Kg, increased to 259.52mOsm/Kg at t0, 264.82mOsm/Kg at t96, and 266.64mOsm/Kg at t140hours.
Temperature remained uniform across three levels of the 5 racks tested under standard conditions and after 105 consecutive back door openings. In a simulated A/C failure (lab temp rising from 23ºC to 29ºC overnight), internal incubator temps were unaffected. A 1-hour power supply interruption test caused a 1.7ºC temperature drop, recovering in 2 hours. A 3-minute front door opening led to a 0.7ºC drop, with full recovery in 1 hour.
HCHO and total VOC levels were similar to those of a reference benchtop incubator (<0.025 ppm).
Conclusions
The automated incubator showed high stability in all tested parameters and embryo development outcomes similar to a standard benchtop incubator. Culture conditions remained uniform across racks with rapid recovery after stress tests.
Impact Statement
This study confirms the reliability of a large high-capacity next-gen automated incubator in maintaining stable conditions critical for embryo culture.