Working in the lab with cellular components, rather than whole cells, the Loring team first found that specific combinations of sugars and proteins known as glycoproteins on stem cells reliably bind to certain lectins. They were then able to exploit this connection to purify cell mixtures.
"When we discovered there was a specific binding pattern, we decided we should just go for it and see whether we could use the lectins to purify cells," said Yu-Chieh Wang, the first author of the research article. "We tested the idea and it works very well, and lectins are readily available and inexpensive."
After identifying the lectin that bound best with stem cells, the group took the work to the next level to show that they could actually separate out stem cells. To accomplish this, they first attached the lectin to tiny beads. Then they exposed these beads to mixtures of stem cells along with non-stem cells.
The researchers used a range of different types of both embryonic stem cells and induced pluripotent cells, which are embryonic stem cell-like cells that are produced by inserting certain genes into skin cells. They included cell lines from both Scripps Research and the labs of their collaborators in Japan and the United States.
In every case, the team found that the stem cells bound remarkably well to the beads, while the cells that washed past were almost all non-stem cells; this meant that both cell types could be collected separately for use in research or in treatments.
Possible uses for the new technique are essentially
|Contact: Mika Ono|
Scripps Research Institute