Cell Rolling Microfluidic Chip Separates White Cells from Whole Blood

The chip works by mimicking the physiological process of ‘cell rolling’ where patterns of adhesive molecules are used to draw out neutrophils (blue) from a stream of blood (red) into a parallel buffer stream as shown in the bottom panel. Images: Suman Bose and Rohit Karnik

The Future of point-of-care diagnostics depends very much on the development of microfluidic devices that can identify specific cell types, spot viruses, and detect inflammation. One challenge has been to separate unique cell types from whole blood, allowing the cells to be scanned for any abnormalities.

Now researchers at MIT have developed a tiny device that filters out leukocytes from whole blood with great specificity. The device uses a cell rolling technique that relies on molecules of  P-selectin, a cell adhesion molecule, to guide the separation process without any complicated laboratory techniques.

Here’s the summary of how the system works from Nature’s open access article:

The device consists of a serpentile channel with two inlet and outlet ports. The cell mixture is injected parallel to a buffer stream into the device and a pure stream of target cells is retrieved from the outlet port. The straight segments of the microfluidic separation channel are patterned with parallel gold stripes grafted with P-selectin, which allows the target cells to interact with the patterns and roll on them. The asymmetry of the patterns with respect to the flow alters the trajectories of the target cells such that they roll along the edge of the pattern (shown with dotted line) and get displaced into the buffer stream.

Here’s from a microscope’s view of the device in action:

Study in journal Scientific Reports: Affinity flow fractionation of cells via transient interactions with asymmetric molecular patterns…

MIT: New microchip sorts white blood cells from whole blood…

Flashback: Microfluidic Microchip Sifts Through Cells Using Rolling Technique…