Since James Thomson of the University of Wisconsin-Madison became the first person to derive and grow human embryonic stem cells in 1998, the accomplishment has remained a considerable challenge for labs. The cells, which can become any cell in the human body, are notoriously finicky.
Now, a team from UW-Madison has developed a fully defined culture system that should result in more uniform cells, according to an article in the journal Nature Methods. Although human embryonic stem cells are not yet approved for use in therapy, the new culture system should also make them safer for such a use.