Before microarrays, scientists “would spend months figuring out how one gene expresses itself in one tissue,” says Garwin.

Microarrays may also help in finding the genetic defects that cause certain diseases. Now, cells from non-cancerous and cancerous tissue can be analyzed so scientists have an idea of what caused the cancer to develop.

Such technology might one day help in understanding and treating human disease.

Drugs can have different effects on people who have slightly different genes. By finding out which forms of a gene a person has, the type and dosage of a drug can be chosen for maximum effectiveness.

“You focus on the average target, and some people deviate from the target,” says Jeruzalmi. But by analyzing individual genomes, he says, “you can synthesize the variant that’s going to be the best for you.”

Such advances, however, rely on further understanding how the proteins in a cell interact with each other, and being able to find the sequences of large genomes quickly.

“It would not shock me if 10 to 15 years from now, if you wanted to, you could go into a doctor’s office and get your DNA sequenced for two thousand dollars,” he says.

—Staff writer Nura A. Hossainzadeh can be reached at hossainz@fas.harvard.edu.