Ontario researchers say after decades of research they've discovered the "motherlode" stem cell that has the potential to endlessly replenish human blood and better treat diseases.

The research, published Friday in the journal Science, moves scientists closer to the hope of helping leaukemia patients who are forced to wait -- some until it's too late -- for bone marrow transplant matches, said principal investigator Dr. John Dick, a senior scientist at Toronto's University Health Network.

"Ever since stem cell science began, scientists have been searching for the elusive motherlode -- the single, pure stem cell that could be controlled and expanded in culture (i.e. grown in a lab) prior to transplantation into patients," Dick said in a statement Friday.

Stem cells are so powerful, one can regenerate the entire blood system of a mouse.

"We have isolated a single cell that makes all arms of the blood system, which is key to maximizing the potential power of stem cells," said Dick, who has been working towards this discovery for 23 years.

He said the life-producing cells are so rare -- about one in every 100,000 blood cells -- it's like finding a needle in a haystack.

"These new findings are a major step to generate sufficient quantities of stem cells to enable greater clinical use and thus move closer to realizing the promise of regenerative medicine for patients."