Holger Müller's microscope has a name fit for mythology: Theia, after the ancient Greek Titaness of light and radiance. And with good reason. The UC Berkeley physicist has just pulled off something that hasn't been done before—adapting a Nobel Prize–winning imaging technique to the electron microscope, creating what he calls "the Formula 1 microscope," and potentially unlocking a new frontier in how scientists see the proteins that make life possible.
Nearly a century ago, the introduction of phase contrast to optical microscopy revealed cellular structures that had been invisible, work so transformative it earned a Nobel Prize in 1953. Now, UC Berkeley physicists have brought that same elegant principle to electron microscopy, which magnifies objects roughly 10,000 times more than optical light. The breakthrough centers on a laser phase plate—a device that uses the world's most intense, focused continuous-wave laser to interact with the electron beam and shift its phase, dramatically boosting contrast for the tiniest molecules.
The timing matters enormously. Cryoelectron microscopy, or cryo-EM, revolutionized structural biology a decade ago and accelerated drug discovery across the world. Yet it has always had a critical limitation: it struggles to produce clear images of small molecules, including most human proteins. The laser phase plate promises to shatter that ceiling, enabling scientists to image proteins down to one-third the size of those that currently challenge existing machines.
But the real excitement lies in cryo-EM's younger sibling, cryoelectron tomography, or cryo-ET. This technique assembles multiple angular views of a protein into a 3D reconstruction, allowing scientists to study molecules in their natural environment—crowded inside living cells—rather than in isolation. "It's like a forest of trees, and you're trying to find one leaf on one tree in there," said Bridget Carragher, founding technical director of imaging at Biohub in Redwood City, California. "Cryo-ET needs a dramatic step forward in contrast, so we can start to see what's going on inside the cell. That's what the laser phase plate promises to give us."
Müller's Theia microscope is already outfitted with the laser phase plate and achieving results. The instrument boasts extra electron optics that give it better resolution than standard cryo-EM even before the laser enhancement is added. Meanwhile, Carragher's team at Biohub is developing a complementary system featuring dual perpendicular laser beams operating at half power each—a design that reduces the risk of component burnout and minimizes optical distortions. Both groups are collaborating with Thermo Fisher Scientific, the primary manufacturer of cryo-EM machines, to bring this technology toward broader adoption.
The implications ripple outward in multiple directions. Structurally, scientists will soon be able to study the majority of human and animal proteins that have, until now, been too small to analyze effectively. Practically, faster drug discovery hinges on understanding protein structures at unprecedented detail. And fundamentally, this advances the quest to see biology as it actually exists—not simplified and stripped of context, but in the magnificent complexity of the living cell. Müller and his Berkeley team published their newest images and technical details in Science on June 11. The microscope named after the goddess of light has turned on to reveal what was hidden.