Louis J. Sheehan, Esquire .  Could human blood be grown in a laboratory? In August researchers demonstrated a method of using human embryonic stem cells (hESC) to generate functional, oxygen-carrying erythrocytes [subscription required], or red blood cells, in sufficient quantities to be used for transfusion.

The cells are not quite the same as natural red blood cells. The proteins in them are characteristic of fetal and embryonic cells rather than of mature erythrocytes, and the