title: Advances in quality control: mouse embryo morphokinetics are sensitive markers of in vitro stress.
abstract: OBJECTIVE
  Can time-lapse analysis of cell division timings [morphokinetics (MK)] in mouse embryos detect toxins at concentrations that do not affect blastocyst formation?
  
  
  CONCLUSIONS
  An MK algorithm enhances assay sensitivity while providing results 24-48 h sooner than the traditional mouse embryo assay (MEA).
  
  
  BACKGROUND
  Current quality control testing methodology is sensitive but further improvements are needed to assure optimal culture conditions. MKs of embryo development may detect small variations in culture conditions.
  
  
  METHODS
  Cross sectional-control versus treatment. Mouse embryo development kinetics of 466 embryos were analyzed according to exposure to various concentrations of toxins and toxic mineral oil.
  
  
  METHODS
  Cryopreserved 1-cell embryos from F1 hybrid mice were cultured with cumene hydroperoxide (CH) (0, 2, 4, 6 and 8 µM) and Triton X-100 (TX-100; 0, 0.0008, 0.0012, 0.0016 and 0.002%). Using the Embryoscope, time-lapse images were obtained every 20 min for 120 h in seven focal planes. End-points were timing and pattern of cell division and embryo development. The blastocyst rate (BR) was defined as the percentage of embryos that developed to the expanded blastocyst stage within 96 h.
  
  
  RESULTS
  BR was not affected for embryos cultured in the three lowest concentrations of CH and the four lowest concentrations of TX-100. In contrast, a unique MK model detected all concentrations tested (P < 0.05). The MK model identified toxicity in two lots of toxic mineral oil that did not affect BR (P < 0.05).
  
  
  CONCLUSIONS
  A limited number of toxins were used so that the results may not apply to all potential embryo toxins. A larger sample size may also demonstrate other statistically significant developmental kinetic parameters.
  
  
  CONCLUSIONS
  MKs in mouse embryos are a sensitive and efficient method for quality control testing of in vitro culture conditions. BR, the end-point of traditional quality control assays, did not detect sublethal concentrations of toxins in the culture milieu in our study. This study demonstrates that temporal variation at key developmental stages reflects the quality of the culture environment. An MEA that incorporates MK will provide enhanced sensitivity and faster turn-around times.
authors.affiliation: Department of Obstetrics and Gynecology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: H S
authors.initials: HS
authors.lastname: Wolff
authors.forename: J R
authors.initials: JR
authors.lastname: Fredrickson
authors.forename: D L
authors.initials: DL
authors.lastname: Walker
authors.forename: D E
authors.initials: DE
authors.lastname: Morbeck
mesh_terms: D000818:Animals; D001555:Benzene Derivatives / Q000633:toxicity; D002455:Cell Division / Q000502:physiology*; D046149:Embryo Culture Techniques / Q000592:standards*; D051379:Mice; D008899:Mineral Oil / Q000633:toxicity; D017830:Octoxynol / Q000633:toxicity; D011786:Quality Control; D013312:Stress, Physiological; D059008:Time-Lapse Imaging; D018675:Toxicity Tests / Q000379:methods
chemical_list: D001555:Benzene Derivatives; D008899:Mineral Oil; D017830:Octoxynol; C007164:cumene hydroperoxide
keywords: embryo culture; morphokinetics; quality control; time-lapse imaging; toxicity