Linking large and small

Connecting microfluidic devices may not be as problematic in the future as it is now. Although microfluidic devices are becoming increasingly widespread in analytical chemistry, successfully interfacing them with standard sample introduction is still a major challenge. To address this problem, Gang Chen and Joseph Wang from New Mexico State University, US, have developed a simple and effective sample introduction interface for capillary electrophoresis microchips.

By relying on a sharp sample-inlet tip placed alternately into sample and buffer solutions, the new device allows a series of samples to be loaded directly, electrokinetically, into the separation microchannel. This avoids the need for complex microchannel layouts and hardware modifications that standard sample introduction requires. The result is highly reproducible sample insertion and rapid replacement of different samples with no apparent carry over.

The new system shows great promise for high-speed microchip analysis, and Chen and Wang expect to achieve even higher precision and separation efficiency by using automated operation and smaller sample plugs.

Rowena Milan.