Rolling in the chip
Cell rolling is a common mechanism cells use to navigate through the body. During inflammation, for example, the endothelial cells that line blood vessels present certain molecules that attract white blood cells just enough to divert them from the rest of the vessel’s cellular traffic. White blood cells then roll along the vessel wall, slowing down to help in the healing of inflamed areas. Researchers at MIT and Brigham and Women’s Hospital have now designed a cell-sorting microchip that takes advantage of this natural cell-rolling mechanism. The device takes in mixtures of cells, which flow through tiny channels coated with sticky molecules. Cells with specific receptors bind weakly to these molecules, rolling away from the rest of the flow, and out into a separate receptacle. The cell sorters, about the size of postage stamps, may be fabricated and stacked one on top of another to sift out many cells at...