Figure 3.

A. Schematic of a cell deformed in a dual-beam optical trap. At low laser power (top), the cell is simply trapped. At higher laser power (bottom), photons colliding with the cell provide enough momentum to physically stretch the cell. B. Free-body diagram describing optofluidic rotation. A dual-beam optical trap immobilizes a cell at a position offset from the center of the microchannel. The velocity profile applies a shear stress to one side of the cell, causing the cell to rotate around the axis of the laser beams. C. Schematic of a deformability cytometry stretching chamber (top) and time lapse of a cell in such a chamber (bottom) (Darling & Carlo, 2015). Cells enter an intersection of two high-speed flows from the left and right, and are deformed and imaged before exiting through the outlets at the top and bottom. Adapted with permission from (Darling & Carlo, 2015) D. Schematic of a real-time deformability cytometry constriction channel (top) and time lapse of a cell in such a channel (bottom) (Otto et al., 2015). Cells enter the narrow channel at high speed, where the shear rate is high enough to deform the cell into a bullet-like shape. Adapted with permission from (Otto et al., 2015)