October 27, 2012
Lab On A Chip Allows For Molecule Measuring With The Naked Eye
[ Watch the Video: Lab on a Chip Simplifies Diagnostic Testing ]
April Flowers for redOrbit.com - Your Universe Online
For example, when someone develops liver cancer, very subtle differences are introduced into the person's bloodstream. This increases the concentration of a particular molecule by just 10 parts per billion. Such a small shift is difficult to detect without sophisticated lab equipment. The new LOAC reveals the presence of ultra-low concentrations of a target molecule.
The findings, reported in the journal Analytical Chemistry, reveal that the team's new technology detected as little as a single nanogram — one billionth of a gram — of the target molecule from a drop of liquid. Instead of sending the sample to the lab for chemical analysis, the chip will allow researchers to measure with such precision using their own eyes.
“The nice thing about the system that we have developed is that this could be done anywhere,” Woolley said. “Somebody could put the sample in, look at it, and have the result they need.”
The innovation Woolley's team devised is simple, line a tiny pipe with receptors that will catch a specific molecule and allow others to pass by. Place a drop of liquid on the clear chip and capillary action will draw the fluid through the channel, flowing up to one centimeter per second. Space in the pipe will constrict as more target molecules are snagged by the receptor, eventually stopping the flow completely.
A direct indication of the concentration of the target molecule is seen in how far the sample flows into the pipe. The shorter the distance traveled, the higher the concentration of molecule.
“The accuracy gained with this system should make it competitive with more expensive and complicated immunoassay systems,” said Chuck Henry, a chemist at Colorado State University.
Woolley's team hopes that their prototype will work as a blueprint for making diagnostic tests for a variety of diseases and genetic disorders inexpensively.
“There are a lot of molecules associated with diseases where concentrations around a nanogram per milliliter or less in blood are the difference between a disease state versus a healthy state,” Woolley said.