title: Identification and isolation of embryonic stem cells in reproductive endocrinology: theoretical protocols for conservation of human embryos derived from in vitro fertilization.
abstract: BACKGROUND
  Embryonic stem cells (ESC) are pluripotent cells obtained from the inner cell mass (ICM) of blastocysts derived from in vitro culture associated with reproductive endocrinology therapy. Human ESCs are regarded as highly significant since they retain the capacity to differentiate into any of approximately 200 unique cell types. Human ESC research is controversial because to acquire such cells, the ICM of human blastocysts must be manipulated in a way that renders embryos nonviable and unsuitable for transfer in utero. Techniques to yield competent ESCs with conservation of source blastocysts would satisfy many objections against ESC research, but at present such approaches remain largely untested.
  
  
  CONCLUSIONS
  We contrast experimental culture of single blastomeres obtained by 1) non-destructive biopsy of embryos destined for transfer, and 2) isolation of karyotypically normal blastomeres from disaggregated ("dead") embryos considered unsuitable for transfer, and evaluate these approaches with regard to production of ESCs. Pluripotency was confirmed by morphological criteria and by quantification of divergent homeodomain proteins specific to undifferentiated cell development. Following ESC isolation and identification, assessment was conducted according to a novel ESC grading system, also proposed here.
  
  
  CONCLUSIONS
  The role of reproductive endocrinology in ESC research remains paramount. In this report, we hypothesize new and expand on existing strategies having the potential to enhance human ESC isolation, identification and in vitro maintenance.
authors: Georgia Reproductive Specialists LLC, Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Atlanta Medical Center, Atlanta, Georgia 30342, USA. dr.sills@ivf.com
authors: Eric Scott
authors: ES
authors: Sills
authors: Takumi
authors: T
authors: Takeuchi
authors: Noriko
authors: N
authors: Tanaka
authors: Queenie V
authors: QV
authors: Neri
authors: Gianpiero D
authors: GD
authors: Palermo
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology; D053624:Blastocyst Inner Cell Mass / Q000166:cytology; D001757:Blastomeres; D002469:Cell Separation / Q000379:methods*; D033041:Embryo Research / Q000941:ethics*; D053595:Embryonic Stem Cells; D005307:Fertilization in Vitro; D006801:Humans; D042282:Microdissection; D008954:Models, Biological; D009030:Mosaicism; D011057:Politics; D046509:Tissue Culture Techniques; D014022:Tissue Survival