Measurement of Single Cell Mass Based on Transient Motion by Dynamic Dielectrophoretic Field

We propose to develop a noninvasive and inexpensive method for measuring single cellmass on the basis of transient motion analysis using an optically-induced dielectrophoresis(ODEP) and microvision-based platform.Our group has uniquely modeled the transient motion of biological cells by the first-ordertransient motion response using a rudimentary ODEP and microvision-based platform. A kernelfunction is derived to describe this transient motion. This function can be generally matched tothe experimental data for Raji cells and red blood cells (RBCs) by measuring two parametersbased on the physical properties of cells: the initial velocity and the transient time-constant. Thecells’ transient response characteristics can be used to track the cell motion trajectory accurately,at the same time permitting simultaneous identification and sorting of different types of cells.Our preliminary work shows that transient motion analysis is an effective and flexiblemethod for research into the physical properties of single cells. The ultimate goal of this project isto demonstrate automated and effective microvision methods for the ODEP platform, which linksa microfluidic system with an embedded ODEP chip, to rapidly analyze the cells’ transientmotion, and then calculate the single cell’s mass.To achieve the ultimate goal of this project, we must explore several fundamental issuesrelated to this noninvasive measurement technique. We must 1) understand and accurately modelcells’ transient projectile motion response, including electrokinetic phenomena and light-inducedelectrothermal forces under the ODEP force field; 2) develop robust microvision-based motiontracking algorithms to detect the cell’s motion in 3D space including translation and rotation, forthe microscopic image sequences analysis; 3) study the relationships between the ODEP forceand the transient motion response and the kinetic characteristics of cells for quantitative analysisof the different types of cells; and 4) study and optimize the ODEP parameters to stimulate theprojectile motion of cells and thus obtain optimum motion data for the measurement of single cellmass. The project team will perform detailed experimental work and numerical simulations tounderstand and solve these fundamental problems through the funding of this project.The key deliverables of this project will be as follows: a) a custom-built ODEP platform topermit the automated measurement of single cell mass; b) a dedicated ODEP chip that worksjointly with the ODEP platform to stimulate cells’ projectile motion in cellular medium; c) asoftware algorithm based on microvision technology to automatically detect the volume of cellsin the microfluidic system and to track the 3D motion of cells in the medium for the single-celltransient motion response analysis; and d) an in-depth understanding of the ODEP-based transientmotion response through cross-validation of experimental and simulation data obtained from theproject.We believe that the new technologies developed from this project will provide an entirelynew paradigm for the measurement of single cell mass and properties, which will in turn findpotential applications in the advanced fields of cellular heterogeneity research, cancer cellidentification, and cell growth studies at various developmental stages.