In a series of trials, the researchers found that two of their sensors reliably signaled the presence of estrogenic compounds. The first, "sensor 2," differentiated between compounds that activate and those that block estrogen receptors, glowing more brightly in the presence of one and dimming when bound to the other. A second bioengineered molecule, "sensor 6," fluoresced in the presence of both types of compounds, making it a reliable indicator of chemicals that bind to the receptor.
When incubated in human cells, the sensors responded to estrogenic compounds within a few hours, Zhao said, with the fluorescent signals gradually increasing in strength up to 24 hours. "And also the sensitivity is pretty high," he said. "Of course it depends on the compound that you're testing; different compounds will have different affinities. But for a truly estrogenic compound, we can detect at the nanomolar level, a very low level."
These are the first such sensors to work in human cells without costly additional chemical steps, he said.
The new sensors will help researchers and clinicians quickly and efficiently determine whether a food, drug or chemical substance interacts with estrogen receptors in human cells, Zhao said.
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign