A device that filters cancer cells from human blood using sound could help to identify tumour cells that have spread.
Finding tumour cells in the blood indicates a cancer has metastasised – but the molecular markers that are used to identify the cells can modify them and make them unsuitable for studying how treatment is proceeding and for performing basic cancer research.
So Itziar González at the Institute for Acoustics in Madrid, Spain, and colleagues developed an alternative: a tiny vibrating plastic chamber through which a blood sample flows. The vibrations create a standing wave that deflects cells in the blood to a different degree depending on their size. Tumour cells are often larger than blood cells and so collect in a different region of the device. The process does not alter the cells.