Development and validation of an automated robotic system for preparation of embryo culture dishes.

OBJECTIVE: To study the development and clinical validation of the ART Pipetting Robot for the IVF Laboratory (APRIL), a liquid-handling robot customized for the precise preparation of microdroplet culture dishes in the field of in vitro fertilization (IVF). DESIGN: A prospective randomized study conducted at an academic IVF center comparing mouse and human embryo outcomes and quantitative measures of accuracy in embryo dishes prepared using APRIL compared with standard manual preparation. SETTING: Academic IVF center. SUBJECTS: The study involved the assessment of the automated culture dish preparation system, APRIL, compared with manual preparation methods in the context of IVF treatment. INTERVENTION: ART Pipetting Robot for the IVF Laboratory is an enclosed liquid-handling robot equipped with custom three-dimensional-printed adapters and designed to dispense embryo culture media and mineral oil into microdroplet culture dishes. MAIN OUTCOME MEASURES: The study evaluated the precision and consistency of APRIL in culture dish preparation by looking at droplet mass, pH of prepared media droplets, and mouse and human embryo development rates. Clinical implementation was assessed by comparing embryo development and outcomes in dishes prepared by APRIL and human embryologists. RESULTS: Compared with embryo culture dishes prepared using standard manual procedures, embryo culture dishes prepared using APRIL demonstrated a greater than 10-fold improvement in consistency (coefficient of variation, 0.46% vs. 6%-7%), maintained optimal pH levels (pH range, 7.281-7.33 vs. 7.275-7.311), and had a greater mouse embryo blastocyst rate (100% vs. 90%-91%). Human embryos cultured in dishes prepared by APRIL had a higher rate of development on days 3 (92.4% vs. 82.6%) and 5 (19.75% vs. 15.57%), and a total number of usable embryos (50.3% vs. 46.1%) compared with manually prepared dishes, although the last two outcomes did not reach statistical significance. CONCLUSION: The results suggest that the use of an automated robotic system for preparation of embryo culture dishes may improve accuracy and outcome measures while reducing the need for trained laboratory personnel to prepare the dishes manually.

Early detection of cryostorage tank failure using a weight-based monitoring system.

PURPOSE: To study the relationship between liquid nitrogen loss and temperature in cryostorage dewars and develop an early-warning alarm for impending tank failure. METHODS: Cryostorage dewars were placed on custom-engineered scales, and weight and temperature data were continuously monitored in the setting of slow, medium, and fast rate-loss of LN2 to simulate three scenarios of tank failure. RESULTS: LN2 Tank weights and temperatures were continuously monitored and recorded, with a calculated alarm trigger set at 10% weight loss and temperature of - 185 °C. With an intact tank, a 10% loss in LN2 occurred in 4.2-4.9 days. Warming to - 185 °C occurred in 37.8-43.7 days, over 30 days after the weight-based alarm was triggered. Full evaporation of LN2 required ~ 36.8 days. For the medium rate-loss simulation, a 10% loss in LN2 occurred in 0.8 h. Warming to - 185 °C occurred in 3.7-4.8 h, approximately 3 h after the weight-based alarm was triggered. For the fast rate-loss simulation, a 10% weight loss occurred within 15 s, and tanks were depleted in under 3 min. Tank temperatures began to rise immediately and at a relatively constant rate of 43.9 °C/h and 51.6 °C/h. Temperature alarms would have sounded within 0.37 and 0.06 h after the breech. CONCLUSIONS: This study demonstrates that a weight-based alarm system can detect tank failures prior to a temperature-based system. Weight-based monitoring could serve as a redundant safety mechanism for added protection of cryopreserved reproductive tissues.

A high-resolution molecular-based panel of assays for identification and characterization of human embryonic stem cell lines.

Meticulous characterization of human embryonic stem cells (hESC) is critical to their eventual use in cell-based therapies, particularly in view of the diverse methods for derivation and maintenance of these cell lines. However, characterization methods are generally not standardized and many currently used assays are subjective, making dependable and direct comparison of cell lines difficult. In order to address this problem, we selected 10 molecular-based high-resolution assays as components of a panel for characterization of hESC. The selection of the assays was primarily based on their quantitative or objective (rather than subjective) nature. We demonstrate the efficacy of this panel by characterizing 4 hESC lines, derived in two different laboratories using different derivation techniques, as pathogen free, genetically stable, and able to differentiate into derivatives of all three germ layers. Our panel expands and refines a characterization panel previously proposed by the International Stem Cell Initiative and is another step toward standardized hESC characterization and quality control, a crucial element of successful hESC research and clinical translation.

Increased efficiency of preimplantation genetic diagnosis for infertility using "no result rescue".

OBJECTIVE: To improve preimplantation genetic diagnosis (PGD) accuracy by using "no result rescue" (NRR) consisting of the reanalysis of dubious results with additional probes binding to a locus different from the one previously analyzed. DESIGN: Prospective study of PGD cycles with and without reanalysis of inconclusive results. SETTING: PGD laboratory. PATIENT(S): Patients undergoing PGD for infertility or Robertsonian translocations. INTERVENTION(S): Nuclei from day 3 biopsied embryos were analyzed with fluorescence in situ hybridization for chromosomes X,Y, 13, 15, 16, 17, 18, 21, and 22. When inconclusive results were obtained, NRR was performed. In addition, 100 PGD cycles using NRR were matched to controls according to maternal age, previous failed cycles, number of zygotes, number of eggs, and date of retrieval. MAIN OUTCOME MEASURE(S): Determination of frequency of inconclusive results and error rate after use of additional probes. Comparison of frequency of inconclusive results with prior PGD results when NRR was not used. Assisted reproductive technology outcome was compared between PGD using NRR and controls not using PGD. RESULT(S): After analysis of 34,831 blastomeres from 34,225 embryos, 2,609 blastomeres (7.5%) showed inconclusive results. After NRR on those 2,609 blastomeres, the number of cells with inconclusive results was reduced to 3.1% (P<.001). After the introduction of NRR, fluorescence in situ hybridization errors, measured as discrepancies between the PGD diagnosis and the analysis of the nonreplaced embryo, decreased from 13.6% to 4.7% (P<.001). PGD with NRR significantly improved implantation rates, from 20% to 31%, and reduced spontaneous abortions from 27% to 6%. CONCLUSION(S): The use of NRR has been proven to be a powerful tool to reduce the error rate and the frequency of inconclusive results in PGD, both parameters of high importance to assess quality of PGD laboratories. Indeed, these parameters are two of the few measurable criteria to measure PGD laboratories. In a parallel controlled study, PGD with NRR significantly improved implantation rates and reduced spontaneous abortions, showing that PGD is more efficient in selecting embryos that will reach term.

Improved implantation after preimplantation genetic diagnosis of aneuploidy.

The objective of this study was to assess the improvement in implantation rates after preimplantation genetic diagnosis (PGD) of numerical abnormalities for the sole indication of advanced maternal age when compared with a control group. Each PGD patient was matched to a control patient according to several parameters prior to obtaining pregnancy results. The diagnosis was based on the analysis of chromosomes X, Y, 13, 15, 16, 18, 21 and 22 plus a ninth probe (1, 7, 14 or 17) on a single cell per embryo. The results were also analysed in relation to the previous number of IVF cycles and the number of dipronucleated zygotes obtained, when replacing presumptively chromosomally normal embryos on day 4 of development. It was found that women of advanced reproductive age (average age 40 years) had a higher implantation rate (18%) than their matched controls treated with standard IVF (11%) (P < 0.05). This increase was not observed in patients with two or more previous IVF cycles or patients with fewer than eight zygotes. Patients with eight or more 2PN zygotes and one or no previous cycles showed the greatest improvement in implantation rate, from 8.8% in controls to 19.2% in the PGD group (average age 40 years) (P < 0.025).