Scientists say it could change modern medicine. Opponents dismiss it as playing God, the ethical equivalent of Nazi death-camp experiments.
Stem-cell research - which involves exploring the use of cells as possible therapies for a range of diseases - is nothing if not contentious, and this week Britain moved into the heart of the controversy by setting up the world's first "bank" for storing and distributing the tiny fragments of proto-life.
The idea is to provide a repository for these scientifically valuable stem cells that researchers the world over can "withdraw" and use without having to go through the scientific and legal hurdles of generating their own.
The UK Stem Cell bank, based at a facility just north of London, could help accelerate therapies for a wide range of genetic disorders and regenerative treatments. The bank, set up with $4.6 million of state money, will position Britain at the forefront of the science, capitalizing on its long history of pioneering work in genetics and its robust legal, regulatory, secular, and institutional framework.
But opponents say the process of creating embryos only to exploit them for therapeutic purposes is abhorrent. "We believe evil should never be done even though good may come of it," says Josephine Quintavalle of the ProLife Alliance in London. "Plenty of good [scientific] ideas came from the extermination of victims of Nazi concentration camps."
Stem-cell research involves harvesting embryos within the first two weeks of their creation, when young cells have the potential to develop into any organ. Researchers hope to use the cells both to "grow" replacement organs and identify genetic imperfections that lead to illnesses like Huntington's disease or Alzheimer's. Most embryos harvested in this fashion are "spare" matter from in vitro fertilization (IVF) programs.
But the process of producing stem cells is so laborious and time-consuming that only a few dozen "lines" exist in the world at the moment.
The bank, based at Britain's National Institute for Biological Standards and Controls, will make this highly limited resource much more widely available, by culturing the stem-cell lines "deposited" by researchers and systematically distributing them to licensed scientists around the world.
"What's important is that there are so few high-quality stem-cell lines available in the world," says Stephen Minger, director of the Stem Cell Biology Laboratory at the Centre for Neuroscience Research, King's College, London.
"Part of the problem is growing these cells," says Dr. Minger, whose lab has produced one stem cell from around 80 embryos. "It's difficult, time-consuming, and labor-intensive."
Since scientists will be able, through the bank, to "share" stem cells, it will reduce dramatically the number of embryos required. It will also facilitate a comparison of results. "It's opening up the potential of working on stem cells to a vastly larger group of scientists," says Alf Game, head of genetics at the Biotechnology and Biological Sciences Research Council, a government agency that helped set up the bank.
So why is Britain positioning itself as the global capital of the new science? The country has a long, strong history of pioneering work in reproductive sciences. The first mammal cloned from an adult cell - Dolly the sheep - was the work of an Edinburgh research institute.
Britain was the first country to permit cloning to create embryos for stem-cell research. It has worked assiduously to create a legal and regulatory framework to minimize moral equivocation. And it has a huge pharmaceuticals sector hungry for test results. (Stem-cell research can also provide important clues as to drug efficacy in patients.)
"Britain traditionally has had a very strong research base in genetics and developmental biology," says Mr. Game. "We punch way above our weight internationally in this field. We had for 40 to 50 years a tradition of outstanding science in this area."
The secularity of the country has also given an added impetus to the science's development in Britain. "Stem-cell research has been very widely supported by the religious communities here too, based on the factual evidence that embryos do not have a moral status of human beings," says Prof. Colin Blakemore, chief executive of the Medical Research Council, which cofounded the bank.
Compare that to countries with strong pro-life lobbies like the US, where IVF is completely unregulated, but where President Bush has banned the use of public money for stem-cell research since 2001; or Italy and other Catholic countries where the embryo is sacrosanct.
There could be a reverse brain-drain effect from countries hostile to stem-cell research into Britain.
"It has already happened," says Professor Blakemore, citing as a prime example Roger Pederson, a leading expert from California who came to Britain two years ago "because of the regulatory environment in his own country."
But Minger says that it takes a lot for an established researcher to uproot himself and ship his laboratory halfway around the world. "I'm pessimistic about people doing that," he says.
One fear about the technology is that cloning could be abused to reproduce humans. Another argument raised by the pro-life lobby is that cells harvested from adults offer similar scientific potential without violating the ethical sanctity of the embryo.
"Our belief is that adult stem-cell technology is leaping ahead, is already at therapeutic levels, whereas embryonic stem-cell research is at the hypothetical level," says Ms. Quintavalle. She says that one eminent Portuguese neuropathologist, Carlos Lima, is already using cells from the upper nasal cavity to address spinal problems.
But scientists counter that "reworking" an adult cell can be extremely difficult and of limited value. Minger says that it is in the embryonic cells that the greatest potential for medicine lies.
"The therapeutic potential of these cells is huge," he says. "They are the only cell type that we know that have almost unlimited capability to turn into all the cells we need for therapeutic applications."
He dismisses fears of clandestine cloning. "I have to account for every embryo I use," he says, noting that his laboratory has used some 80 embryos thus far. "My reward will come when we have therapies; I am a great beneficiary of an enlightened policy in this country."