ObjectiveTo assess survival of blasts that were vitrified, thawed, TE biopsied and cultured overnight.DesignPatients having two or more day 5 blasts vitrified between 2005 and 2011, who have opted to donate embryos via consent, were included in the study. Donor egg and prior PGS embryos were excluded from the study.Materials and methodsOocytes were retrieved, placed in Fert Media (Sage), hyaluronidased after 2 to 3 hours, ICSI'ed 1 to 3 hours following hyaluronidase and placed into Cleav Media (Sage). All embryos were cultured individually. On day 3, embryos were placed into Blast Media (Sage). Untransferred blasts were vitrified for future use. Upon thaw, embryos were placed in 20%SPS Blast Media (Sage). Approx. four hours post thaw, the blasts were examined for survivability and TE biopsy was performed. A ZILOS-tk laser was used during the TE biopsy procedure. Embryos were cultured overnight under low O2 in 10%SPS Blast Media (Sage). Approx. 28 hours post thaw, embryos were observed again for survivability and transferability.ResultsTabled 1N (# Thawed)56Initial Survival53 (94.6%)Overnight Survival49 (92.5%) Open table in a new tab ConclusionThis study demonstrates high competency of blasts vitrified, thawed, biopsied and cultured overnight. This is useful information for clinics and patients that have undiagnosed, vitrified blasts in storage and would now like to return and apply PGS testing during an FET cycle. Provided PGS testing can be accurately performed overnight, euploid blasts can be identified and transferred. With enhanced PGS turnaround testing time, this is a unique, novel approach that has promising future potential. ObjectiveTo assess survival of blasts that were vitrified, thawed, TE biopsied and cultured overnight. To assess survival of blasts that were vitrified, thawed, TE biopsied and cultured overnight. DesignPatients having two or more day 5 blasts vitrified between 2005 and 2011, who have opted to donate embryos via consent, were included in the study. Donor egg and prior PGS embryos were excluded from the study. Patients having two or more day 5 blasts vitrified between 2005 and 2011, who have opted to donate embryos via consent, were included in the study. Donor egg and prior PGS embryos were excluded from the study. Materials and methodsOocytes were retrieved, placed in Fert Media (Sage), hyaluronidased after 2 to 3 hours, ICSI'ed 1 to 3 hours following hyaluronidase and placed into Cleav Media (Sage). All embryos were cultured individually. On day 3, embryos were placed into Blast Media (Sage). Untransferred blasts were vitrified for future use. Upon thaw, embryos were placed in 20%SPS Blast Media (Sage). Approx. four hours post thaw, the blasts were examined for survivability and TE biopsy was performed. A ZILOS-tk laser was used during the TE biopsy procedure. Embryos were cultured overnight under low O2 in 10%SPS Blast Media (Sage). Approx. 28 hours post thaw, embryos were observed again for survivability and transferability. Oocytes were retrieved, placed in Fert Media (Sage), hyaluronidased after 2 to 3 hours, ICSI'ed 1 to 3 hours following hyaluronidase and placed into Cleav Media (Sage). All embryos were cultured individually. On day 3, embryos were placed into Blast Media (Sage). Untransferred blasts were vitrified for future use. Upon thaw, embryos were placed in 20%SPS Blast Media (Sage). Approx. four hours post thaw, the blasts were examined for survivability and TE biopsy was performed. A ZILOS-tk laser was used during the TE biopsy procedure. Embryos were cultured overnight under low O2 in 10%SPS Blast Media (Sage). Approx. 28 hours post thaw, embryos were observed again for survivability and transferability. ResultsTabled 1N (# Thawed)56Initial Survival53 (94.6%)Overnight Survival49 (92.5%) Open table in a new tab ConclusionThis study demonstrates high competency of blasts vitrified, thawed, biopsied and cultured overnight. This is useful information for clinics and patients that have undiagnosed, vitrified blasts in storage and would now like to return and apply PGS testing during an FET cycle. Provided PGS testing can be accurately performed overnight, euploid blasts can be identified and transferred. With enhanced PGS turnaround testing time, this is a unique, novel approach that has promising future potential. This study demonstrates high competency of blasts vitrified, thawed, biopsied and cultured overnight. This is useful information for clinics and patients that have undiagnosed, vitrified blasts in storage and would now like to return and apply PGS testing during an FET cycle. Provided PGS testing can be accurately performed overnight, euploid blasts can be identified and transferred. With enhanced PGS turnaround testing time, this is a unique, novel approach that has promising future potential.