title: Vitrification of mouse and human blastocysts using a novel cryoloop container-less technique.
abstract: OBJECTIVE
  To vitrify mouse and human blastocysts with use of the cryoloop procedure and to assess subsequent development.
  
  
  METHODS
  Controlled study of vitrification of mouse and human blastocysts.
  
  
  METHODS
  Research department of a private assisted reproductive technology unit.
  
  
  METHODS
  Blastocysts that were not suitable to be frozen were donated from patients.
  
  
  METHODS
  Culture of pronucleate embryos in sequential media to the blastocyst stage.
  
  
  METHODS
  Survival of the vitrification procedure was assessed by reexpansion, hatching, and outgrowth in culture. In addition, the viability of mouse blastocysts was assessed after transfer to pseudopregnant recipients.
  
  
  RESULTS
  Vitrification of mouse blastocysts did not affect the ability to reexpand, hatch, or outgrow in culture. Furthermore, implantation rates and fetal development were equivalent for nonfrozen and vitrified blastocysts. Vitrified human blastocysts were able to hatch and outgrow in culture at rates similar to nonfrozen controls.
  
  
  CONCLUSIONS
  Cryoloop vitrification was able to cryopreserve mouse and human blastocysts without any reduction in the ability to reexpand and hatch in culture. Furthermore, viability was not reduced by the cryoloop vitrification of mouse blastocysts.
authors.affiliation: Colorado Center for Reproductive Medicine, Englewood 80110, USA. mlane@colocrm.com
authors.forename: M
authors.initials: M
authors.lastname: Lane
authors.forename: W B
authors.initials: WB
authors.lastname: Schoolcraft
authors.forename: D K
authors.initials: DK
authors.lastname: Gardner
mesh_terms: D000818:Animals; D001755:Blastocyst; D015925:Cryopreservation / Q000379:methods*; D046508:Culture Techniques; D005260:Female; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D013045:Species Specificity