(339c) High-Throughput Linear Optical Stretcher for Mechanical Characterization of Blood Cells

Cell mechanical properties are a label-free biomarker capable of indicating cell health. Differences in individual cell deformability in cases such as cancer, malaria, and sickle cell anemia have been used to differentiate between normal and diseased cell state. Established individual cell measurement techniques are typically low throughput, making acquisition of statistically relevant population data impractical. To overcome this limitation, we have developed a linear optical stretcher as a high-throughput mechanical property cytometer. Custom, inexpensive, scalable optics image a linear diode bar source into a microfluidic channel, where cells are hydrodynamically focused into the optical stretcher. Upon entering the stretching region, antipodal optical forces deform cells in flow. Each cell relaxes as it flows out of the trap and is compared to the stretched state to determine deformation. The deformation response of untreated red blood cells and neutrophils were compared to chemically treated cells. Statistically significant differences were observed between normal, diamide-treated, and glutaraldehyde-treated red blood cells, as well as between normal and cytochalasin D-treated neutrophils. Based on the behavior of the pure, untreated populations of red cells and neutrophils, a mixed population of these cells was tested and the discrete populations were identified by deformability.