One million vocalists singing the same song will sound cacophonous to an audience member if the singers belt out the tune at different tempos.

“But if you’re listening to one person sing, and he changes his tempo, you’re still going to stay in tune with him,” said Meni Wanunu, an assistant professor of physics in Northeastern’s College of Science.

Wanunu used the analogy to explain the difference between older and newer gene sequencing techniques. Old techniques, he said, analyzed millions of DNA molecules at a time. But new techniques take a single-molecule approach, a strategy that has the potential to revolutionize the field — once a few significant challenges are overcome.

By obtaining the sequence of an organism’s genetic material with ease, scientists can explore a range of research areas, from correlating genes with functions to answering evolutionary mysteries. Doctors can use gene sequencing to test for specific genes that are related to specific diseases, such as breast and ovarian cancers. Patients could learn in their home what foods to avoid and which drugs would be most effective for them.