A blastocyst, the early stage of an embryo from which stem cells are usually extracted, destroying it in the process. Image: British government

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MELBOURNE, 24 August 2006: Stem cells can be harvested from very young embryos without destroying them, meaning that one of the major ethical objections to embryonic stem cell research could be removed.

Today, Robert Lanza's group at Advanced Cell Technologies - a private company in Worcester, Massachusetts – reported their findings in the journal Nature. The authors say the technique not only clears a moral hurdle, it offers parents who conceive in the test-tube a chance to provide their child with a lifetime supply of matched embryonic stem cells.

In January 2006, the researchers reported that they could successfully derive embryonic stem cells from mouse embryos without destroying them. Today's publication extends that feat to human embryos.

The technique takes advantage of embryo biopsy - a standard procedure in test-tube baby clinics. One cell from an eight cell embryo is gently prised away from the cluster to be tested for a genetic disease like Cystic Fibrosis. The remaining group of seven, none the worse, carry on developing. If the biopsy shows the embryo to be disease free, then it is implanted into a uterus with every chance of producing a normal baby.

What Lanza's group have achieved is to take the single cell or blastomere, and coax it to become an endlessly proliferating stem cell: plenty of cells to biopsy, plenty of cells for anything. Although the cells cannot form a new embryo, they can, according to preliminary tests, form the major types human tissue just as bone fide embryonic stem cells do.

What coaxes the blastomere to become an embryonic stem cell? In a case of cellular dominoes, it is other human embryonic stem cells mixed in with mice embryonic cells known as fibroblasts. The primer human embryonic stem cells are tinted fluorescent green, a property that allows them to be sorted away from the newly generated embryonic stem cells.

The new technique has a 33 per cent success rate, as long as the embryos are healthy-looking to start with. This is comparable to current techniques that destroy embryos.

Though the report is undoubtedly a technical and scientific breakthrough, some researchers are dubious as to its value. Says embryologist Alan Trounson at Monash University, "I'm not sure when you'd ever use it; we can only use surplus frozen embryos and they are destined to be discarded anyway. And it would cost [prospective parents] a fortune to do it. The reaction from my colleagues down at the IVF clinic is: no thank-you."

Lifting the current ban on embryonic stem cell research is currently the topic of much debate in Australian politics, with a former health minister, Kay Patterson, threatening to introduce a bill to allow the research, contrary to the policy of her own, governing party.