HONG KONG - SCIENTISTS in Singapore have developed a strategy to 'clean up' embryonic stem cells, which researchers hope can one day be used to replace damaged tissues and for other tailor-made personal treatments. Embryonic stem cells are master cells that can grow, or 'differentiate", into any type of cell or tissue, and are subsequently transplanted into the body. But some studies have shown that residual stem cells that fail to differentiate can turn cancerous later on. In the journal Stem Cells, scientists in Singapore said they generated antibodies that successfully killed off these residual stem cells in mice. 'Although...