Bone marrow transplants that are delayed because of a lack of blood cells could benefit from a new way of multiplying the cells, scientists in Montreal say.

If more bone marrow stem cells were available, it could help the nearly 4,000 people who wait in vain for a bone marrow transplant every year in North America.

In Thursday's issue of the journal Cell, Dr. Guy Sauvageau of the University of Montreal said they produced a large number of blood stem cells in the lab from a smaller sample taken from bone marrow.

"It could be possible to envision transplants for all adults from existing umbilical cord blood banks," Sauvageau said in a release.

To produce more stem cells in the lab, the researchers identified 10 proteins naturally found in the cells, after checking 700. They used these 10 proteins to force the stem cells to multiply. Bone marrow produces blood cells.

It's also possible that the larger number of transplanted marrow stem cells could help to prevent rejection of transplanted organs, Sauvageau said, based on the results of mouse studies.

Next, scientists at the Montreal's Maisonneuve-Rosemont Hospital plan to test whether the technique works in humans.

The study was funded by the Canadian Institutes of Health Research.