A health ministry team has developed technology to safely and effectively reproduce stem cells from umbilical cord blood.

The new technology may increase the success rate of stem cell transplantation, which is used to treat serious illnesses such as leukemia, ministry officials said Saturday. Clinical tests using the new technique are planned for leukemia patients.

The technology is also expected to be useful in reproducing bone marrow stem cells, lessening the burden on bone marrow donors.

The Health, Labor and Welfare Ministry team was able to reproduce cord blood stem cells 30 times in 12 days by mixing interleukin-6 and three other proteins in the cord blood. The reproduction rate is about four times faster than a similar method developed overseas.

Stem cells grown using this method did not become cancerous, officials said, adding the safety of the technology has been confirmed.

Umbilical cord blood stem cells have the potential to treat a host of serious illness.