Microfluidic Devices for the High-Throughput Chemical Analysis of Cells

TLDR

A microfluidic platform was developed that integrates hydrodynamic cell loading, electric‑field lysis, and on‑chip electrophoretic separation and fluorescence detection of cytosolic dyes in Jurkat cells. The device achieved complete cell lysis in <33 ms, separated dyes in ~2.2 s with <1 % migration time reproducibility and 2300–4000 plates efficiency, analyzed 139 cells (≈9 % showing distinct hydrolysis), and reached 7–12 cells/min—over 100× faster than conventional capillary electrophoresis.

Abstract

A microfluidic device is reported that integrated cell handling, rapid cell lysis, and electrophoretic separation and detection of fluorescent cytosolic dyes. The device function was demonstrated using Jurkat cells that were loaded with the fluorogenic dyes − carboxyfluorescein diacetate, Oregon green carboxylic acid diacetate, or Calcein AM. The loaded cells were hydrodynamically transported from the cell-containing reservoir to a region on the microfluidic device where they were focused and then rapidly lysed using an electric field. Complete lysis was accomplished in <33 ms. The hydrolyzed, fluorescent dyes in the cell lysate were automatically injected into a separation channel on the device and detected 3 mm downstream of the injection point. The total separation time was ∼2.2 s with absolute migration time reproducibilities of <1% and efficiencies ranging from 2300 to 4000 theoretical plates. Results from 139 cells are reported. A small fraction of these cells, ∼9%, were found to enzymatically hydrolyze the loaded dyes in a manner significantly different from the majority of the cells. Cell analysis rates of 7−12 cells/min were demonstrated and are >100 times faster than those reported using standard bench-scale capillary electrophoresis.