If it lives up to its promise, the chip should help make cloning cheap and easy enough for companies to mass-produce identical copies of the best milk or meat producing animals for farmers. It might even be used for cloning human embryos.

The chip automates the laborious process of nuclear transfer, the key step in cloning. At present it takes hours of painstaking work with a microscope to remove the nucleus of an egg cell and replace it by fusing the denucleated egg with another cell.

"If somebody's got something like that, obviously it would make everybody's life easier," says Tanja Dominko of Advanced Cell Technology, the Massachusetts company that caused a stir late last year when it announced that it had created cloned human embryos.

In animals, cloning is still very wasteful. At best, around half of cloned embryos develop to the point where they can be implanted, and only a tenth of these survive to birth. Often more than a hundred nuclear transfers must be carried out to create a single clone.

Scientists usually start with a batch of 150 eggs, and denucleate them one at a time before moving on to the next step. That means eggs can be left sitting around for several hours, a delay that may reduce success rates.

But the nuclear transfer array developed at Aegen Biosciences, by the company's founders Richard Kuo and Gregory Baxter, could handle hundreds or even thousands of eggs at once. Kuo says they can routinely denucleate 30 to 50 sea urchin eggs at a time. They plan to start testing cow eggs in the next few weeks.

The prototype is a thin silicon slice a few centimetres across etched with hundreds of tiny wells, one for each egg. The trick is to spin the chip in a centrifuge, forcing the eggs' dense nuclei through a small hole at the bottom of each well. About 9
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Contact: Claire Bowles
claire.bowles@rbi.co.uk
44-207-331-2751
New Scientist
30-Jan-2002