Scientists at McMaster University have discovered how to make human blood from adult human skin. 

The discovery could mean that people needing blood for surgery, cancer treatment or treatment of blood conditions like anemia will be able to have blood created from a patch of their own skin to provide transfusions. Clinical trials could begin as soon as 2012.

The researchers have also shown that the conversion is direct. Making blood from skin does not require the middle step of changing a skin stem cell into a pluripotent stem cell that could make many other types of human cells, then turning it into a blood stem cell. 

The discovery was replicated several times over two years using human skin from both young and old people to prove it works for any age of person.

Citation: Eva Szabo, Shravanti Rampalli, Ruth M. Risueño, Angelique Schnerch, Ryan Mitchell, Aline Fiebig-Comyn, Marilyne Levadoux-Martin, Mickie Bhatia, 'Direct conversion of human fibroblasts to multilineage blood progenitors', Nature November 7th 2010 doi:10.1038/nature09591