A laser shining through human cells is changed by what it encounters mostly mitochondria, the so-called power packs of the cell. When these changes are displayed by a spectrometer, researchers at Sandia National Laboratory can see obvious differences between healthy and cancerous cells. In healthy cells, the mitochondria cluster around the nucleus. In unhealthy cells, they are scattered about, isolated, and balled up in a quiescent state.
It helps that the laser generates light at about 800 nm, a frequency little absorbed by cells and a close match in size to mitochondria. Researchers have determined that mitochondria cause 90 to 95% of the light scattering from this technique. This real-time method can serve as a highthroughput way of identifying cancerous liver cells. This is a considerable improvement over the century-old method currently used microscopic examination of stained cells, which can take days to complete and generates many false readings.
The new technique still needs work. It must be adapted to handle cancer cells in fluids taken directly from the body. It could also find use detecting when stem cells differentiate into nerve cells, muscles, and other tissues.