3D fluid confined sample stream coulter flow cytometry

摘要

A microfluidic flow cytometry device includes a substrate and transverse electrodes formed on the substrate. An elastomer microfluidic focusing channel system formed on the substrate focuses a sample stream onto the floor of an outlet channel that is substantially wider and taller than cells or particles of interest and that has the transverse electrodes disposed in its floor upstream of an exit site. A step in the outlet channel upstream of the transverse electrodes vertically confines sample stream flow onto the floor of the outlet channel over the transverse electrodes. Buffer inlet channels introduce a buffer stream for horizontal focusing of the sample stream into the central region of the outlet channel at the transverse electrodes. A sample inlet channel is smaller in vertical height than the buffer inlet channels for introducing a sample stream such that the buffer vertically focuses the sample stream away from the top of the outlet channel. Sensitivity of detection is good enough to conduct both qualitative and quantitative analysis. Detection and analysis circuitry can be optimized to conduct analyze real and imaginary impedance at frequencies optimized toward tagged particles and or cells, and assays are possible.