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April 12, 2005
Laser beams sort stem cells and cancer cells by springinessTopics: Medicine
Measuring the "stretchiness" of cells using a new laser technique promises to pinpoint human stem cells in blood and distinguish cancerous cells from benign ones. This new technology, although strictly a diagnostic tool, could turn out to be one of our most important methods in fighting cancer. After all, we can't fight what we don't know about. Imagine being able to pick out cancerous cells from biopsies as small as just 50 cells, when traditional methods need between 10,000 and 100,000 cells to give a diagnosis. And even better, the researchers say this is the first test able to identify metastatic cancer cells - those which are prone to spreading through the body to form secondary tumours - without actually locating any metastatic tumours. Now we're talking about very early detection which translates to earlier treatment and greater opportunities for success.
(...) Using an "optical stretcher", which pushes and pulls individual cells to measure their elasticity, Josef Käs and Jochen Guck from the University of Leipzig in Germany successfully separated adult stem cells from human blood.
(...) Cells from most organisms have an internal scaffolding, called a cytoskeleton, which keeps their shape and helps them move. But this structure is less strong in cells which either have no reason to organise themselves, like primitive stem cells, or because they "de-differentiate", like cancer cells - which lose the special characteristics of the tissues in which they originated.
(...) This means that stem cells and cancerous cells are more springy than other cells. And metastatic cells are suppler still.
(...) Using the optical technique, cells from a sample are pushed one by one into a gap between two opposing infrared lasers. As the light from each laser beam enters the cell, it changes momentum because the cell has a higher refractive index. This gives the cell a "kick back" .... and when the beam leaves the cell it gives it a "kick forward".
Other coverage - BBCNews (UK)
Cross posted at NewHopeBlog
Posted by Hyscience at April 12, 2005 1:45 PM
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