DNA microscopy offers entirely new way to image cells

Traditionally, scientists have used light, x-rays, and electrons to peer inside tissues and cells. Today, scientists can trace thread-like fibers of nerves throughout the brain and even watch living mouse embryos conjure the beating cells of a rudimentary heart. But there's one thing these microscopes can't see: what's happening in cells at the genomic level.

Now, biophysicist Joshua Weinstein and colleagues have invented an unorthodox type of imaging dubbed "DNA microscopy" that can do just that. Instead of relying on light (or any kind of optics at all), the team uses DNA "bar codes" to help pinpoint molecules' relative positions within a sample.

With DNA microscopy, scientists can build a picture of cells and simultaneously amass enormous amounts of genomic information, Weinstein says. "This gives us another layer of biology that we haven't been able to see."

"You're basically able to reconstruct exactly what you see under a light microscope," Weinstein says. The two methods are complementary, he adds. Light microscopy can see molecules well even when they're sparse within a sample, and DNA microscopy excels when molecules are dense – even piled up on top of one another.

He thinks DNA microscopy could one day let scientists speed the development of immunotherapy treatments that help patients' immune systems fight cancer. The method could potentially identify the immune cells best suited to target a particular cancer cell, he says.