Microelectrophoresis platform for fast serial analysis of single cells.

A capillary-based microelectrophoresis platform for fast serial analysis of single cells is described. In this system, the capillary remains fixed and a two-channel flow system is used to rapidly switch the buffer surrounding the capillary inlet from a physiological buffer to an electrophoretic buffer. Single cells are retained in the physiologic buffer channel utilizing an array of cell microwells patterned into the channel floor. The defined addresses of the cells on the array enable the sequential delivery of individual cells to the inlet of the capillary, where a focused laser pulse lyses the cell. The cell chamber is moved along a preordained route so that the inlet of the capillary is located in the electrophoresis buffer for separation and the physiological buffer during cell sampling. The throughput of the current system is limited by peak overlap between successive samples. Key characterizations of this system including the fluid flow rates, the cell array dimensions, and laser energies were performed. To demonstrate this system, 28 cells loaded with Oregon green and fluorescein were serially analyzed in under 16 min, a rate of 1.8 cells/min.