Abstract: A device for characterizing a cell or particle includes a channel having an inlet and an outlet, the channel containing a moving fluid therein for carrying the cell or particle from the inlet to the outlet. The device includes a detector for detecting the presence of a cell or particle along portion of the channel, the detector including a first detecting position, a second detecting position, and a third detecting position. The device further includes a light source providing an optical gradient disposed within the channel and between the second and third detecting positions. A control system is coupled to the detector to receive and process detected signals from the detector. During operation, the amount of time that a cell or particle takes to flow through a first distance (i.e., its time-of-flight) is measured. The cell or particle is then flowed past a second, downstream distance in the presence of an optical gradient and its time-of-flight is measured.

Abstract: Optophoretic methods are used to determine one or more biological properties or changes in biological properties of one or more cells or cellular components. The methods use optical or photonic forces to select, identify, characterize, and/or sort whole cells or groups of cells. The methods are useful in a number of applications, including, but not limited to, drug screening applications, toxicity applications, protein expression applications, rapid clonal selection applications, biopharmaceutical monitoring and quality control applications, cell enrichment applications, viral detection, bacterial drug sensitivity screening, environmental testing, agricultural testing, food safety testing, as well as biohazard detection and analysis.