Researchers at the Virginia Bioinformatics Institute (VBI) at Virginia Tech have developed a disposable microchip that replaces space-consuming instrumentation with fast, cost-effective, lab-on-a-chip technology. The microfluidic device is suitable for large-scale screening of disease-related biomarkers. Protein biomarkers are useful as “molecular indicators” for a wide range of diseases including breast cancer. The lab-on-a-chip integrates a pump, valve, separation column, and detection interface onto a 3- by-1 inch glass microchip and delivers a performance to match benchtop instrumentation typically occupying a few square feet of lab space.

Iuliana Lazar, assistant professor at VBI, commented: “Microfluidic devices have emerged as powerful and reliable analysis platforms for proteomic applications and biomarker screening. The miniature format as well as the ability to manipulate small amounts of sample result in short analysis times and significant reductions in cost.” Dr. Lazar added: “Using the microchip that we have developed in our laboratory, sample injection, separation, labeling and detection can be performed routinely in a few minutes. Increased specificity and sensitivity are paving the way for high-throughput testing that will permit screening at the population level for prognostic or diagnostic markers for a whole range of diseases. “

The system combines liquid chromatographic separation of proteins driven by hundreds of parallel micro- and nanochannels. These channels, which have dimensions in the micrometer domain, serve to generate an electroosmotic flow. This flow of liquid helps to separate the proteins which are then identified by state-of-the-art mass spectrometric detection instruments. Researchers in Dr. Lazar’s laboratory used the microchip to detect cancer biomarkers in cellular extracts generated from the MCF7 breast cancer cell line. 77 proteins were identified with confidence, five of which are known to be cancer-specific biomarkers. The fully integrated microfluidic liquid chromatography system has been shown to be suitable for the detection of multiple disease-specific biomarkers.

An article, “Microfluidic liquid chromatography system for proteomic applications and biomarker screening,” by Lazar, P. Trisiripisal, and H.A. Sarvaiya, was published in the August 15, 2006 issue (vol. 78, no. 15) of Analytical Chemistry. A patent application entitled “Microfluidic devices and methods facilitating high-throughput, on-chip detection of separation techniques” has been filed with the US patent office.

This research was supported by a National Science Foundation Career Grant no. BES-0448840.

Virginia Tech (Virginia Polytechnic Institute and State University)