BBC Human blood from stem cells

Scientists say making red blood cells is still way off By BBC Science's Andrew Craig

Scientists in the United States have succeeded in turning embryonic stem cells into the precursors of blood cells.

The work, the latest advance in stem cell research, might point the way to the eventual production of blood cells for transfusions.

What researchers at the University of Wisconsin-Madison have done is to push stem cells, taken from human embryos, along the path to becoming blood cells.

They did it by exposing the stem cells - tissue that has yet to specialise as any part of the developing body - to bone marrow and growth-promoting chemicals.

The stem cells then became what scientists call haematopoietic precursor cells.

Vital ingedients

In the body's natural condition, these go on to form colonies of red blood cells, which carry oxygen around the body; white blood cells, which fight disease; and platelets, which clot the blood at the site of an injury.

All three are vital ingredients of blood that is used in transfusions.

But Dan Kaufman, who led the research, stresses that producing blood cells for transfusion in useful quantities is a long way off.

In recent months, other researchers have succeeded in turning stem cells into heart and kidney tissue.

But as the pace of research quickens, some religious and political groups maintain their ethical objections to the use of human embryos to provide the stem cells that are its raw material.

Attempts will continue to bypass the controversy by isolating and retrieving stem cells from living adult bodies.

-- Anonymous, September 03, 2001