Device is able to detect single cancer cells in a blood sample

The microfluidic device, described in the 17 March online edition of the journal Small, could allow doctors to quickly determine whether cancer has spread from its original site. It could also be used to detect viruses such as HIV.

It could eventually be developed into low-cost tests for doctors to use in developing countries where expensive diagnostic equipment is hard to come by, said Mehmet Toner, professor of biomedical engineering at Harvard Medical School.

Toner built a version of the device four years ago. In that version, blood taken from a patient flows past silicon posts coated with antibodies that stick to tumour cells. Any cancer cells that touch the posts become trapped although some of the cells might not encounter the posts at all.

Toner believed that if the posts were porous, cells could flow right through them, making it more likely they would stick. To achieve that, he enlisted Brian Wardle, an MIT associate professor of aeronautics and astronautics, who often utilises carbon nanotubes when designing advanced materials.