A group of scientists at Pressure BioSciences Inc., South Easton, Mass., has developed a method of sample preparation using high water pressure that can detect food contaminants.


The technique is called pressure cycling technology and employs cycles of hydrostatic pressure up to 35,000 pounds per square inch to safely and efficiently release biomolecules such as DNA, RNA and proteins off of products including food, plant and biological samples. These biomolecules can be extracted within minutes, allowing for more accurate downstream testing of pathogens or contaminants.


“We’re working on instrumentation that has even higher pressure,” said Nate Lawrence, vice president of marketing and business development with Pressure BioSciences. “Water is compressible to 8% at 35,000 pounds per square inch. Imagine squeezing a sponge over and over to relieve pressure on the sponge. That’s what this is like.”


Lawrence said much of the work with the process is being used in work with soil samples.


“The U.S. Department of Agriculture in Washington state is processing soil, looking for fungi that affects wheat,” Lawrence said. “They’ve reported a greater extraction of DNA (with PCT).”


Lawrence added that there were groups looking at using PCT to detect huanglongbing disease — more commonly referred to as greening — from citrus samples.


“Any other sampling process would have to get inside the plant, release the organism and then release the DNA for further analysis,” Lawrence said. “It’s difficult to break open spores and dump out the cellular contents so they can be analyzed. This process is much faster and more efficient.”


Lawrence said the “holy grail” for his research would be to develop a test that, once foodborne pathogens were detected, could ascertain the viability of those pathogens.


“Sample processing in general has lagged behind detection methods available,” Lawrence said. “We’re bringing a new level of sensitivity and new level of preparation for sampling.”