Development of a MEMS-fabricated SU-8 device for 2D separations

摘要

A polymer based biochip for rapid 2-D separations of peptides, proteins, and other biomedically relevant molecules was designed and fabricated. Like traditional 2D polyacrylamide gel electrophoresis (2D-PAGE) methods, the device will allow molecules to separate based on isoelectric point (pI) and molecular weight (MW). The design, however, integrates both an initial capillary isoelectric focusing (cIEF) step followed by capillary electrophoresis (CE) in multiple parallel channels, all on a single microfluidic chip. Not only is the "lab-on-a-chip" design easier to use and less expensive, but the miniaturization of the device produces very rapid separations, on the order of seconds. Fluorescence detection will be used in the preliminary stages of testing, but the device is also equipped with integrated electrodes in the electrophoresis channels to perform multiplexed electrochemical detection for quantitative analysis. We present the chip design and fabrication, as well as the initial test results demonstrating cIEF and CE with one analyte. Furthermore, we introduce preliminary work on the use of a polyacrylamide gel in the electrophoresis channels.