Yale researchers are using magnetic nanoparticles and an external B field to create waves in a liquid full of cells of various shapes and sizes. By regulating this process, the technology is able to sort the cells by their basic characteristics.
The Technology Review Blog explains:
In experiments described this week in the Proceedings of the National Academy of Sciences, the Yale researchers made microfluidic channels lined with magnetic-field-generating electrodes. Cells were then added to a ferrofluid in the channel. When magnetic fields were applied along the device, the particles in the fluid pushed the cells along the channel, separating them by size and shape. Something similar can be accomplished using electrical fields, says Koser, but this can damage the cells. His group used the device to separate live blood cells from sickle cells and bacteria.
Koser believes the device could be especially helpful when trying to detect very rare types of blood cell, such as cancerous ones. Rapidly sorting cells using magnetic fields could improve the sensitivity of tests for these rare cells without adding any costly chemical labels. Tumor cells are squishier than healthy ones–possibly because they grow quickly and so don’t form a proper internal cell skeleton–and Koser hopes that magnetic fields will also be able to separate cells based on their elasticity and other mechanical properties.
More from Technology Review Blog: Magnetic Liquid Separates Blood Cells
Abstract in PNAS: Label-free cellular manipulation and sorting via biocompatible ferrofluids