UC Berkeley

The physical attributes of a cell can serve as label-free biomarkers of cellular state and be- havior. In cancer, for example, malignant cells are known to be significantly more deformable than their non-malignant counterparts. I describe the development of two microfluidic platforms: Multi-Zone Visco-NPS (mz-visco-NPS) and Combo-NPS. Both approaches utilize Node-Pore Sensing (NPS), in which the ohmic resistance across a microfluidic channel is used to characterize and measure single-cell parameters. Mz-visco-NPS uses multiple sinu- soidal contraction segments aligned in series to periodically deform passing cells at increasing perturbation frequencies. Using this platfrom, I measure the rheology of human breast epithelial cells, namely the elastic storage (G’) and viscous loss (G”) moduli. Combo-NPS uses DNA-directed patterning for the positioning of surface-immobilized antibodies upstream of a linear contraction channel. In this design, I demonstrate the ability to measure single-cell surface-marker expression, in addition to mechanical properties such as diameter, elasticity, and viscosity. I generate paired immuno- and mechano- phenotype datasets on single cells that enable new approaches for subpopulation screening and correlation studies. Ultimately, both platforms are powerful tools for moderate-throughput, multimodal, single-cell biophysical phenotyping.