A novel trophectoderm biopsy technique for all blastocyst stages

Abstract

Purpose This study was conducted to assess the effectiveness of a new trophectoderm (TE) biopsy method that does not require prior opening of the zona pellucida at the blastocyst stage. Methods TE biopsy was conducted using a modified extrusion method for embryos during the cleavage stage. In this method, culture medium was injected into the perivitelline space to help extrude TE cells from the zona pellucida before TE biopsy. Results Our extrusion method preserves the embryo culture environment until immediately before biopsy because it does not require opening of the zona pellucida prior to TE biopsy. Furthermore, this method does not require a waiting time for blastocyst hatching after laser irradiation, thereby minimizing damage to the embryos and maintaining the time schedule of culture operations. Conclusions TE biopsy using this novel extrusion method may be useful in various applications, including the collection of TE cells for next‐generation sequencing analysis.

Impact of Freeze-Thawing, Cell Collection, and Laser Irradiation Cycles on Mosaicism Occurrence in Preimplantation Genetic Testing for Aneuploidy

“…A biopsy is generally performed by aspirating the required amount of TE cells and cutting them by laser irradiation (pulling method) or rubbing them into a holding pipette ( icking method). In this study, we used the pulling method [9] as previous studies indicated that the icking method collects more TE cells than those obtained by the pulling method [7]. The pulling method irradiates the targeted area with a laser, making cell collection easy to control and, thus, ensuring a more accurate collection of the intended number of cells.…”

“…Biopsies were performed using the pulling method with laser irradiation [9]. Regarding embryo biopsies, tubing, and NGS analyses of cell samples obtained from trophectoderm (TE) biopsies, these were performed as described by Mizobe et al [9] and Takeuchi et al [10].…”

“…Biopsies were performed using the pulling method with laser irradiation [9]. Regarding embryo biopsies, tubing, and NGS analyses of cell samples obtained from trophectoderm (TE) biopsies, these were performed as described by Mizobe et al [9] and Takeuchi et al [10]. Brie y, embryos were suspended with the holding pipette, and laser irradiation (90 µs) was used from the 3 o'clock position to create a small opening in the zona pellucida (at a site containing more TE cells).…”