Systems Array Developed to Detect Minute Amounts of Proteins

A capillary electrophoresis system has been used to identify and characterize different proteins.

The system uses capillary isoelectric focusing (cIEF) with laser-induced fluorescence detection. The apparatus has been set up as a multiplexed array and has proved to be well suited to high-throughput analysis.

The multiplexed capillary electrophoresis system employs an array of 32 capillaries with a micromachined sheath-flow cuvette as the detection chamber. The sample streams were simultaneously excited with a 473-nm laser beam, and the fluorescence emission was imaged on a charge-coupled device (CCD) camera with a pair of doublet achromat lens.

The performance of the technology was excellent as it provided the highest throughput isoelectric focusing analysis ever reported. There was a very high sensitivity for a high-throughput instrument, and excellent resolution separation for capillary isoelectric focusing. The capillary array electrophoresis system produced over six orders of magnitude superior detection limits compared to other systems. The technology will find wide application, including characterization of recombinant and therapeutic proteins, the diagnosis of disease, and the study of systems biology.

Oluwatosin O. Dada, PhD, lead author of the study and a research assistant professor at the University of Notre Dame, (South Bend, IN, USA) was awarded a prize for the best paper published in 2010 in Analytical and Bioanalytical Chemistry, (ABC). The editor of the journal, Prof. Aldo Roda, PhD, said, "There is a highly competitive effort underway in the scientific community to improve the analytical performance of isoelectric focusing (IEF) as a tool for protein separation and concentration. Several groups have investigated the miniaturization of cIEF and the integration of cIEF to a microchip format. This new analytical approach may resolve the ongoing problem of time-consuming procedures.” The paper was originally published on line in ABC on March 25, 2010.

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