Professor Josef Ks and Dr Jochen Guck from the University of Leipzig have developed a procedure that can extract and isolate embryo-quality stem cells from adult blood for the first time. This new technique could unlock the stem cell revolution and stimulate a boom in medical research using stem cells.

Stem cells are cells which have not yet differentiated into specialised tissues such as skin, brain or muscle. They promise a new class of regenerative medicine, which could repair apparently permanent damage such as heart disease or Parkinson's. The cells are currently taken from aborted human foetuses, an issue which has led to controversy and opposition in many parts of the world. Any alternative source, such as voluntary adult donations, could spark a boom in new cures.

Scientists have known for some time that stem cells exist in adult human blood and certain other tissues. However the only reliable way to separate them involved marking the cells with a chemical dye, rendering them useless for medical purposes. Professor Ks' technique for the first time uses a physical characteristic of each cell its stretchiness or elasticity instead of its biological make-up, to decide whether or not it's a stem cell. Stem cells don't need a rigid "cytoskeleton" to hold them in shape, which makes them stretchier than normal cells.

Ks and Guck's machine uses a powerful beam of infrared laser light to stretch and measure cells one by one. His optical stretcher differs from an existing tool known as optical tweezers in which the light is focused to a sharp point to grab hold of a cell. In contrast, the optical stretcher uses un-focused light. This allows laser beams strong enough to detect stretching to be used without
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Contact: David Reid
david.reid@iop.org
44-207-470-4815
Institute of Physics
11-Apr-2005