Electrospray mass spectrometry analysis of blastocoel fluid as a potential tool for bovine embryo selection

PURPOSE: The aim of this study was to analyze the metabolic profiles of blastocoel fluid (BF) obtained from bovine embryos produced in vivo and in vitro. METHODS: Expanded blastocysts (20/group) that were in vitro and in vivo derived at day 7 were used. BF was collected and analyzed under direct infusion conditions using a microTOF-Q(®) mass spectrometer with electrospray ionization and a mass range of 50–650 m/z. RESULTS: The spectrometry showed an evident difference in the metabolic profiles of BF from in vivo and in vitro produced embryos. These differences were very consistent between the samples of each group suggesting that embryo fluids can be used to identify the origin of the embryo. Ions 453.15 m/z, 437.18 m/z, and 398.06 m/z were identified as biomarkers for the embryo’s origin with 100% sensitivity and specificity. Although it was not possible to unveil the molecular identity of the differential ions, the resulting spectrometric profiles provide a phenotype capable of differentiating embryos and hence constitute a potential parameter for embryo selection. CONCLUSION: To the best of our knowledge, our results showed, for the first time, an evident difference between the spectrometric profiles of the BF from bovine embryos produced in vivo and in vitro.