As the abundance of genetically modified (GM) foods continues to grow, so does the demand for monitoring and labeling them. The genes of GM plants used for food are tweaked to make them more healthful or pest-resistant, but some consumers are wary of such changes. To help inform shoppers and enforce regulations, scientists are reporting in ACS’ journal Analytical Chemistry the first comprehensive method to detect genetic modifications in one convenient, accurate test.

Li-Tao Yang, Sheng-Ce Tao and colleagues note that by the end of 2012, farmers were growing GM crops on more than 420 million acres of land across 28 countries. That’s 100 times more than when commercialization began in 1996. But doubts persist about the potential effects on the environment and human health of these biotech crops, created by changing the plants’ genes to make them more healthful or more able to resist pests. In response, policymakers, particularly in Europe, have instituted regulations to monitor GM products. Although researchers have come up with many ways to detect genetic modification in crops, no single test existed to do a comprehensive scan, which is where Yang and Tao come in.

They developed a test they call “MACRO,” which stands for: multiplex amplification on a chip with readout on an oligo microarray. It combines two well-known genetic methods to flag about 97 percent of the known commercialized modifications, almost twice as many as other tests. It also can be easily expanded to include future genetically modified crops.

The authors acknowledge funding from the National Transgenic Plant Special Fund, the Program for New Century Excellent Talents in University, the State Key Development Program for Basic Research of China, the National High Technology Research and Development Program of China, the National Natural Science Foundation of China.