Derivation of human feeders for prolonged support of human embryonic stem cells.

Human embryonic stem (hES) cell lines are derived and propagated using animal-based feeder cells and xenoproteins. Reliance on a xenosupport system introduces many disadvantages with respect to exploiting the therapeutic potential of hES cells because of the risk of transmission of pathogens from the animal feeders to hES cells. Recently, human feeders (commercial and in-house derived) in the presence of human-based culture ingredients have been successfully used to derive and propagate xeno-free hES cell lines. In-house-derived human feeders, however, have the advantage over commercial feeders of not being previously exposed to xeno-proteins. This chapter describes the collection of human tissue biopsies and the establishment of human feeder monolayers for the derivation and support of hES cell lines in the presence of human-based culture ingredients.