Their lucky break came when the cells did, in fact, grow out. In about four weeks, the investigators picked out the new cells and exposed them to a proliferative media. They removed the cells from that media and exposed them to a differentiation media. The cells converted into islet cells and started expressing the master regulator of beta cells that turns on the insulin gene. These cells began producing insulin.
Stem cells are very distinct from other cells.
Stem cells have an incredible capacity to migrate. Sure enough, these NIPs showed a penchant for motility. Once stem cells find their niche, they differentiate when they sense the right amount of growth factors. The MGH team wants to use time-lapse photography to see what the NIPs are doing. Eventually, they would like to know where these stem cells originate.