IN THE LAB

Synthetic Blood On the Way

UK scientists led by the Scottish National Blood Transfusion Service are beginning a three year trial to examine whether stem cell replication could provide an unlimited safe blood supply, untainted by HIV or the human version of mad cow disease. The BBC reports that the scientists, fueled the Wellcome Trust's promised $4.3 million, will use human embryos left over from in vitro fertilization treatments to create the supply. Scientists will test embryos to determine which ones have O negative blood, which is the universal donor group, then culture the cells and remove their nuclei to produce mature oxygen-carrying cells. The U.S. firm Advanced Cell Technology has already managed to produce billions of cells, and now the challenge is to scale up production.