Safer way to make human stem cells

MADISON, Wis., March 27 (UPI) -- U.S. researchers say they've developed a safer way of reprogramming cells to create an alternative to embryonic stem cells.

University of Wisconsin, Madison stem cell researcher James Thomson said previous methods of creating induced human pluripotent stem cells left behind viral vectors and exotic genes, the university said Thursday in a release.

"We believe this is the first time human-induced pluripotent stem cells have been created that are completely free of vector and transgene sequences," says Thomson.

The new method, uses a plasmid rather than a virus to ferry reprogramming genes into adult cells

Thomson, a stem cell pioneer who was the first to successfully culture human embryonic stem cells, said the new method eliminates any genetic artifacts that could compromise therapeutic safety or skew research results.