Evaluation of the TMRW vapor phase cryostorage platform using reproductive specimens and in vitro extended human embryo culture

Embryo Biology

VOLUME 2, ISSUE 3, P268-277, AUGUST 01, 2021


Deirdre M. Logsdon, M.S., Courtney K. Grimm, M.S., William B. Schoolcraft, M.D., Sue McCormick, B.S., Terry Schlenker, M.A., Jason E. Swain, Ph.D., Rebecca L. Krisher, Ph.D., Ye Yuan, Ph.D., Michael G. Collins, Ph.D. 



To assess the impact of shipment and storage of sperm, oocytes, and blastocysts in vapor phase nitrogen compared with static storage in liquid phase nitrogen.


Prospective cohort-matched study.


Multiple in vitro fertilization laboratories in an in vitro fertilization network.


Fifty-eight human embryos, 32 human oocytes, 15 units of bovine semen.


Vapor vs. liquid nitrogen.

Main Outcome Measure(s)

The postwarming survival of oocytes, sperm, and blastocysts, and the developmental potential of blastocysts during in vitro extended culture.


Custom-designed labware, for use with the TMRW platform, enables continuous temperature monitoring during shipment and/or storage in the vapor phase robotic storage system. The highest temperature recorded for specimens shipped to a domestic laboratory was −180.2 °C with a mean ± SD of −190.4 ± 0.5 °C during shipment and −181.1 ± 0.6 °C during storage. Likewise, specimens shipped internationally had a high of −180.2 °C with a mean ± SD of −193.5 ± 0.6 °C during shipment and −181.2 ± 0.7 °C during storage. Results from the extended culture assays have revealed no deleterious effect of shipment and storage in nitrogen vapor. The viability of mammalian gametes and embryos was equivalent between the vapor phase and liquid phase storage.


The evaluated system did not have any deleterious effects on the postwarming survival of sperm, oocytes, and blastocysts. The postwarming developmental potential of human blastocysts during in vitro extended culture was unaffected by storage and handling in the vapor phase nitrogen TMRW platform when compared with static liquid phase nitrogen storage. Our results suggest that the vapor phase cryostorage platform is a safe system to handle and store reproductive specimens for human assisted reproductive technology.