Cryopreservation methodologies: freezing location and protocol alter development of mouse embryos.
The purpose of this study was to determine the effects of location in the freezing chamber and various freezing protocols on post-thaw development of two-cell mouse embryos. Different protocols were used to cryopreserve two-cell mouse embryos in different freezer positions. Embryos were thawed and cultured to observe post-thaw development. When four different freezer positions were compared, one position provided better post-thaw blastocyst development, regardless of several protocols tested. Furthermore, there were significant differences in temperatures between positions in the freezer. These differences came before seeding (-7 degrees C), just before changing the -7.0 degrees C hold demand (Ramp 2), during the two time points tested during Ramp 3 (-0.3 degrees C/min), and during the holding ramp of -30 degrees C. Post-thaw embryo development was improved by lengthening the time after seeding but before decreasing the temperature again. Decreasing embryos' temperature before plunging appeared to improve post-thaw performance.
Boone
William R
WR
Reproductive Endocrinology and Infertility, Greenville Hospital System, 890 W. Faris Rd., Suite 470, Greenville, South Carolina 29605-5601, USA.
Johnson
Jane E
JE
Blackhurst
Dawn W
DW
Higdon III
H Lee
HL
D000818:Animals; D003080:Cold Temperature; D015925:Cryopreservation / Q000295:instrumentation / Q000379:methods* / Q000662:veterinary*; D005314:Embryonic and Fetal Development / Q000502:physiology*; D051379:Mice; D013997:Time Factors