In a major breakthrough, scientists have for the first time grown stem cells from a man's skin using cloning techniques.
While the advancement could reopen the debate over ethics of human cloning, it could also lead to development of tissue in a lab that could be used for treating a wide range of adult diseases, including Alzheimer's.
Scientists cloned a mammal, Dolly the sheep for the first time in 1996.
"What we show for the first time is that you can actually take skin cells, from a middle-aged 35-year-old male, but also from an elderly, 75-year-old male" and use the DNA to create tissue with cells of an exact match, said Robert Lanza, a professor at Wake Forest University School of Medicine.
"I am happy to hear that our experiment was verified and shown to be genuine," said Shoukhrat Mitalipov, a development biologist at Oregon Health and Science University in the US.
Starting with a quality human egg is key to the cloning process, confirmed the study.
The researchers replaced the original DNA in an unfertilised egg with the donor DNA, and then cultured the cells in a lab dish.
They found that the stem cells were an exact match to the donor's DNA and therefore they could then be turned into various tissue types.
"In theory, you could use those stem cells to produce almost any kind of cell and give it back to a person as a therapy," Paul Knoepfler, associate professor at the University of California at Davis was quoted as saying.
The study appeared in the journal Cell Stem Cell.
