You may not be able to get blood from a stone, but you can get it from a tobacco leaf. Or at least researchers at the Energy Dept.'s Pacific Northwest National Laboratory in Richland, Wash., can. It's all a matter of tinkering with the plant's genes.
Pacific Northwest researchers have successfully transplanted the human genes for certain blood-clotting factors into tobacco plants, which were chosen because they are common and well-studied. Most clotting factors now are made from human blood plasma, but infectious diseases, such as hepatitis B and C, flu, and HIV, can be transferred in these products. The tobacco-produced clotting factors, says bioprocessing group manager Daniel Anderson, are not only safer, but obtainable at about one-tenth the cost. "One and a half tobacco plants would produce enough blood factor to treat one hemophilia patient for a year, and a world supply for wound healing could be produced in a few small greenhouses," Anderson says.
So far, Pacific Northwest scientists have developed tobacco-produced coagulation factor VIII, which is used for hemophilia treatments, and thrombin, a clotting enzyme that aids in healing wounds. The blood protein is extracted from the plant leaves and then purified. No animals or humans have been tested yet, and it will likely be several years before the blood factors are available for humans, Anderson says.