COLUMBIA, Mo., Oct. 17 (UPI) -- U.S. scientists say they can detect the spread of skin cancer cells through the blood by literally listening to the cells' sound.
The new, minimally invasive technique developed by researchers at the University of Missouri-Columbia causes melanoma cells to emit noise and could allow oncologists to spot early signs of metastases before the cells settle into other organs.
The team's method, called photoacoustic detection, uses a laser to make cells vibrate and pick up the characteristic sound of melanoma cells.
The Missouri-Columbia researchers were able to detect as few as 10 melanoma cells in saline solution. The dark, microscopic granules of melanin contained in the cancer cells absorb the energy bursts from the blue laser light, going through rapid cycles of expanding as they heat and shrinking as they cool. Those sudden changes generate loud cracks, relative to the granules' size.
The sound waves produced by melanin are high-frequency ultrasounds, meaning they cannot be heard by the human ear, even if amplified. However, researchers can pick them up with special microphones and analyze them with a computer.
The procedure is detailed in the journal Optics Letters.
