The technique, developed by a team from the Department of Energy's Oak Ridge National Laboratory, California Institute of Technology and Protein Discovery, is more than just a novelty, however, as it is useful for separating, concentrating and analyzing proteins quickly with high sensitivity and selectivity.
"With this technique, we can steer DNA or other biomolecules for transport in three dimensions and also separate them according to size and their isoelectric point," said Chuck Witkowski, a co-author and president and chief executive officer of Protein Discovery, a Knoxville startup company. The ability to perform these functions with high efficiency and precision has applications for medical diagnostics and as a discovery tool.
The technique, called photoelectrophoretic localization and transport, or PELT, involves shining a highly focused beam of light on semiconductor material and using electric fields to move the proteins. Force-field traps are created by a photocurrent focused at the illuminated areas of the semiconductor. In contrast to traditional electrophoresis, which uses high voltage, this approach permits researchers to dynamically change characteristics of the electric field in three dimensions in real time using computer-controlled software and low voltage.
"It's kind of like a tractor beam in 'Star Trek,' but this is science, not science fiction," said Nathan Lewis, a co-author and professor at California Institute of Technology.
Photoelectrophoretic is extremely versatile and offers several advantages over methods that use conventional electrophoresis, according to co-author Thomas Thundat of ORNL's Life Sciences Division.