The new findings, appear today (Feb. 17) in the journal Nature Methods and come on the heels of a recent University of California study showing that existing stem cell lines are already contaminated with an animal molecule. The potential threat of animal pathogens tainting human stem cell lines poses a problem for the safe clinical use of many, if not all, of the current cell lines now in use.
Until now, scientists have had to grow and sustain stem cells through the tedious daily task of generating mouse feeder cells from mouse embryos. Feeder cells, or fibroblasts, are connective tissue cells that form the matrix upon which stem cells grow.
The mouse feeder cells were an important ingredient in the mix of culture materials required to keep stem cells in their undifferentiated "blank slate" state. Embryonic stem cells are capable of forming any of the 220 tissues and cells in the human body and, in culture, are constantly trying to migrate down different developmental pathways. Maintaining stock cultures in their undifferentiated state is critical.
The feeder cell dogma now can be overturned, says lead investigator Ren-He Xu, a senior scientist at WiCell, a private, nonprofit research institute. "This work completely gets rid of the need for feeder cells," says Xu. "It also significantly reduces the daily labor of preparing the feeder cell-conditioned medium."
"It is important that the culture of human ES cells be simplified so that the average scientist can use them without extensive prior training," says James Thomson, a UW-Madison professor of a
Source:University of Wisconsin-Madison