High-throughput single-cell rheology in complex samples by dynamic real-time deformability cytometry

Abstract

In life sciences, the material properties of suspended cells have attained significance close to that of fluorescent markers but with the advantage of label-free and unbiased sample characterization. Until recently, cell rheological measurements were either limited by acquisition throughput, excessive post processing, or low-throughput real-time analysis. Real-time deformability cytometry expanded the application of mechanical cell assays to fast on-the-fly phenotyping of large sample sizes, but has been restricted to single material parameters as the Young’s modulus. Here, we introduce dynamic real-time deformability cytometry for comprehensive cell rheological measurements at up to 100 cells per second. Utilizing Fourier decomposition, our microfluidic method is able to disentangle cell response to complex hydrodynamic stress distributions and to determine viscoelastic parameters independent of cell shape. We demonstrate the application of our technology for peripheral blood cells in whole blood samples including the discrimination of B- and CD4+ T-lymphocytes by cell rheological properties.

Microfluidic Fabrication of Click Chemistry-Mediated Hyaluronic Acid Microgels: A Bottom-Up Material Guide to Tailor a Microgel’s Physicochemical and Mechanical Properties

“…In MC-PBS, we determine the elasticity of HA-microgels by performing real-time deformability cytometry (RT-DC) [ 27 ]. While RT-DC has been mainly used to study cells [ 68 , 69 , 70 ], for the first time, we evaluate HA-microgel mechanical properties at high throughput with single-particle resolution ( Figure 7 A). With regards to variations of PEG-crosslinker equivalents, the Young’s moduli of HA-microgel species reveal similar trends as compared to foregoing swelling and permeability studies ( Figure 7 B).…”

A comparison of microfluidic methods for high-throughput cell deformability measurements

“…Moreover, for sDC an integrated FACS-like readout of cell and cell compartment fluorescence is available 47 , as well as a theoretical framework allowing for the extraction of Young’s moduli from deformability data 31 , 48 . Recently developed dynamic RT-DC enables assignment of viscosity to measured cells by analysing the time evolution of cell deformation in the channel 49 . xDC surpasses cDC and sDC with its immense throughput.…”

An optofluidic “tweeze-and-drag” cell stretcher in a microfluidic channel

“…28 Other implementations are to deform the cells when they flow through at a high speed in narrow microfluidic channels, with cross-sectional dimensions close to or smaller than the cell size. [29][30][31][32] Specifically, in the real-time deformability cytometry (RT-DC) technique, the characterization throughput reaches 10 2 -10 3 cells per s. 30 However, the extracted cell stiffness in the RT-DC technique is only valid for cell deformations over a short time scale of ∼1 ms, 33 which is not comparable (around an order of magnitude higher) with the static cell stiffness measured using the conventional static testing. The reason why the cell stiffness measured over a short time scale is different from the static ones can be attributed to that a high deformation rate can lead to fluidization of actin networks and thus significantly affect the mechanical response of the cell.…”