title: New media for culture to blastocyst.
abstract: OBJECTIVE
  To develop sequential media for extended culture of embryos in human IVF, with use of a mouse embryo assay. The BlastAssist system was developed. Blastocyst culture has been our routine method since 1994, using earlier media IVF and M3 in sequence.
  
  
  METHODS
  Experimental laboratory study.
  
  
  METHODS
  University Hospital and university research unit.
  
  
  METHODS
  F1 hybrids between CD1 female and BDF male mice.
  
  
  METHODS
  Two-cell mouse embryos were cultured 4 days in test media; 1 day in phase 1 medium followed by 3 days in phase 2 medium.
  
  
  METHODS
  Percentage of expanded and hatched blastocysts.
  
  
  RESULTS
  Compared with a two-cell block in the old culture system, more than 80% went to the blastocyst stage in the new media. The new medium system was based on a heavily modified low-glucose Earle's balanced salt solution. Additions were pyruvate, lactate, amino acids, human serum albumin, and Synthetic Serum Replacement. In contrast to regular tissue culture cells, embryos required an increased concentration of EDTA. The final media produced a blastocyst frequency of 94% and a day 4 hatching frequency of 71%.
  
  
  CONCLUSIONS
  With the high blastocyst frequency demonstrated here, the combination of blastocyst culture and single ET should be an effective means of treatment in patients and could help to eliminate multiple gestations. The BlastAssist system is commercially available.
authors.affiliation: Department of Obstetrics and Gynecology, In Vitro Fertilization Unit, University Hospital of Northern Norway, and Institute of Clinical Medicine, University of Tromsø, Tromsø, Norway.
authors.forename: Martha
authors.initials: M
authors.lastname: Hentemann
authors.forename: Kjell
authors.initials: K
authors.lastname: Bertheussen
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001755:Blastocyst / Q000378:metabolism / Q000502:physiology*; D016895:Culture Media, Serum-Free / Q000378:metabolism*; D046149:Embryo Culture Techniques; D004624:Embryo Transfer; D047108:Embryonic Development; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D051379:Mice; D009028:Morula / Q000378:metabolism / Q000502:physiology*; D019289:Pyruvic Acid / Q000378:metabolism; D012709:Serum Albumin / Q000378:metabolism; D013997:Time Factors
chemical_list: D000596:Amino Acids; D016895:Culture Media, Serum-Free; D012709:Serum Albumin; D019344:Lactic Acid; D019289:Pyruvic Acid; D005947:Glucose