Human Embryonic Stem Cells

Properties

Undifferentiated cells

  •  Pluripotent
  •  Gene expression markers: Oct-4, SSEA-3, SSEA-4, TRA-1-60, TRA-1-80 positive
  •  Karyotype: must be normal
  •  Growth: exponential growth
  •  Mouse embryo fibroblast (MEF) feeder layer must be of high quality

Characteristics that reflect loss of undifferentiated hES cells

  • Gene expression markers: Flk1 (fetal liver kinase-1 for mesoderm), NCAM  ( neural cell adhesion molecule, ectoderm),  AFP (a- fetal protein, endoderm)
  • Cell fate decision for differentiation can occur within hours. Therefore hES cell cultures require daily monitoring of growth.
  • Factors that influence loss of stemness are:
                - inhibited growth
                - reduced activity of MEF feeder layer
                - large colony size
                - distance to neighboring colonies

Differentiation of hES cells

  •  hES cells are pluripotent and have the ability to give rise to all tissue types of the human body. Refer to the literature for conditions to establish specific differentiated phenotypes.