Toxins and pathogens be warned
Click here for a high resolution photograph.
Imagine munching on a hamburger boldly knowing that it was not contaminated with E. coli or sipping a cold glass of water confident it was truly clean. Due to advances at Pacific Northwest National Laboratory, these ideas may become a reality. A team of PNNL researchers is developing a method to detect contaminants in food, water and air supplies.
Ideally, this research could protect consumers from serious outbreaks involving pathogens like E. coli and toxins that occur naturally in the environment. It also can be used to monitor food safety in the processing environment and detect common toxins or disease-causing bacteria in foods, such as salmonella.
"We want to develop systems that can automatically monitor environmental samples and detect bioagents," said Cindy Bruckner-Lea, a scientist involved in the research. "We'd like to create a device that could be used to protect and ensure safe water, air and food supplies."
The sensor system for detecting biological agents includes three critical components. First, a device developed at PNNL, called BEADS, or Biodetection Enabling Analyte Delivery System, isolates bacteria, spores, viruses and their DNA from environmental samples. Convenience is a major bonus of the BEADS technology, which is fully automated so detectors can analyze samples and monitor for threatening toxins without a person manually preparing the samples.
Next, an antibody is used to purify and concentrate the pathogen or toxin to enable accurate and sensitive detection. This step of the detection process utilizes the PNNL-developed single-chain antibody library, which provides scientists with over one billion artificial antibodies.
Finally, a second antibody, called a reporter antibody, labeled with a fluorescent dye or a fluorescent quantum dot binds to a different region on the toxin or pathogen. The fluorescence of the quantum dot is measured on the bead and can identify the concentration of the toxin or pathogen.
With these detection capabilities, exposure to potentially lethal toxins can be prevented or minimized. Proper treatments can be quickly administered to those who have been in contact with the toxin. "Ideally we'd like to ensure our environment is safe," said Bruckner-Lea.
Eventually, toxin detectors could be inexpensive enough for personal use, but scientists are currently aiming for government and industry applications.