Doctors typically diagnose cancer via a biopsy, which can be invasive and expensive. A better way to diagnose the disease would be to detect telltale tumor cells floating in the bloodstream, but such a test has proved difficult to develop because stray cancer cells are rare, and it’s difficult to separate them from the mélange of cells in circulation.

 

Now researchers from Massachusetts General Hospital and Harvard Medical School say they’ve built a microfluidic device that can quickly grab nearly any type of tumor cell, an advance that may one day lead to simple blood tests for detecting or tracking cancer.