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New MCB and Applied Physics Professor Max Prigozhin is Developing Multicolor Electron Microscopy

New MCB and Applied Physics Professor Max Prigozhin is Developing Multicolor Electron Microscopy

Newly appointed MCB and Applied Physics Professor Max Prigozhin builds microscopes. His long-term goal is to develop a multicolor electron microscopy method that will reveal the dynamics of cell signaling in nanoscale resolution.

Biologists often face a trade-off when choosing a microscope. Fluorescence microscopes, which use light to illuminate samples, can record images of living cells and have a versatile pallet of dyes and fluorescent proteins for highlighting particular molecules. But these microscopes are limited in their ability to show very small features. On the other hand, scanning electron microscopes, which use focused beams of electrons to probe samples, can capture near-molecular level detail but typically do so in monochrome images. In electron microscope images, it is impossible to tell proteins apart.

Prigozhin isn’t satisfied with this dichotomy. “Over a decade worth of very successful efforts have pushed the spatial resolution of fluorescence microscopy to a few tens of nanometers,” he says. “But spatial resolution is not the forte of optical imaging. The question is whether we can turn this problem upside down: what if we start with an imaging technique that naturally has nanoscale resolution and add color to it instead? Electron microscopy already can clearly resolve membranes and organelles inside cells, so it would be very useful to image both proteins and membranes simultaneously.”

MCB faculty are enthusiastic about Prigozhin and his work’s potential for moving molecular biology forward.  “His work straddles the physical and life sciences beautifully, and I am thrilled that MCB is one of his homes,” says MCB faculty and chair Venkatesh Murthy. “His youthful excitement, spark, and drive are sure to enliven our department. Importantly, his appointment signals our serious commitment to soften or break disciplinary boundaries.”

“Max is a spectacular scientist who brings together beautiful new methods to uncover new biology,” MCB faculty Sharad Ramanathan adds. “We expect big things from him, and are privileged to have him as a colleague in both MCB and Applied Physics.”

Originally hailing from the city of Samara, Russia, Prigozhin is the first Russian national to become a tenure-track faculty member in Harvard MCB. A few members of his family were part of Samara’s famous aerospace engineering industry, but, growing up, Prigozhin was more interested in playing guitar than in science and engineering. He’s glad he took a rather indirect route into science. “If you want to make it as, say, a competitive figure skater, you have to start when you’re four years old, and, unless you’re out-skating everybody else by the time you’re five years old, forget it,” he says. “In science, it’s not like that. You don’t necessarily have to be a child prodigy to do well.”

For his undergraduate education, Prigozhin headed to the University of Toronto in Canada, where he majored in chemistry and physics. The professor who made the biggest impression was analytical chemist Ulrich Krull. “Ulli’s analytical chemistry class was like a sold-out show. He’d walk into a full auditorium and say ‘Alright, let’s rock-n-roll!’ and start the lecture. It was amazing,” Prigozhin recalls.

Prigozhin then decided to pursue graduate work in biophysics at the University of Illinois at Urbana-Champaign. The main draw was the prestigious Center for the Physics of Living Cells (CPLC), an NSF Physics Frontiers Center Program. “University of Illinois has one of the strongest biophysics programs in the world,” Prigozhin says. “I was very fortunate to be immersed in this environment for my PhD.”

Prigozhin joined the lab of Martin Gruebele. “Martin suggested that I develop a new instrument to study the biophysics of protein folding,” Prigozhin recalls. “The idea was to apply high pressure to proteins—about twice that of the Mariana Trench and enough to unfold the biomolecule. Then you release the pressure really quickly, in about a microsecond, to see how the protein refolds back into its native structure. It was kind of like building a sophisticated pressure cooker but with no heat.”

He fondly remembers the diversity of the lab: “Martin really did a fantastic job recruiting people from all over the world,” Prigozhin says. “I had colleagues from the US, Germany, Israel, India, China, Vietnam, Russia, Taiwan, and Chile—all in a lab of 10-12 people in total! I really hope that I can emulate this culture in my new lab.”

Despite his focus on biophysics, Prigozhin says he did not do much microscopy until his postdoc with Nobel Laureate Steven Chu at Stanford University. Chu had just returned from a 4-year stint as Secretary of Energy under President Obama when Prigozhin joined the lab. “Steve would never drive to work, always cycle,” Prigozhin says. “Not only that, he would carry his bicycle up the stairs to the third floor every time.”

His mentor’s active lifestyle rubbed off, he adds, pointing at the blue road bike leaning against the wall in his office: “Now I bike to Harvard and feel like I have to carry the bike up the stairs as well,” he says with a smile. “Let’s see if I can keep this up through my first winter here.”

The 2000s and early 2010s had seen the arrival of several game-changing microscopy techniques, so Prigozhin and his colleagues at Stanford decided to develop new nanoparticle tags for multicolor electron microscopy. “When it comes to multicolor electron microscopy, the state-of-the-art is comparable to where fluorescence microscopy was about 30 years ago,” Prigozhin explains. “Imagine doing fluorescence imaging with no GFP and no fluorescent dyes!”

His strategy for achieving multicolor electron microscopy relies on a set of nanoparticles containing rare-earth ions. In this technique, researchers attach these nanoparticles to individual proteins inside a cell. When the microscope’s electron beam reaches one of these nanoparticles, the rare-earth ions in them glow. Prigozhin’s microscopes will be able to record that glow, allowing researchers to see where the attached proteins are. That data can then be integrated with the typical black-and-white electron microscopy data showing membranes and organelles.

“You are shining the electron beam on the sample, and the sample is emitting different types of signals at the same time,” he explains. “We have to collect and decode these signals in parallel to get the full picture.” There are about a dozen rare-earth elements that can be used this way, he adds, so the goal is to construct a microscope that can image at least ten different proteins at once. “Multiplexing is a must for understanding the complexity of biological pathways or untangling the diversity of cell types in the brain,” he says.

Much of his lab, including the optical microscopes and lab benches, is located on the fourth floor of Northwest Building. But Prigozhin is particularly excited about a part of his lab that lies eight floors below in Northwest’s lowest level B4, where not even vibrations from passing red line subway trains will disturb samples or electron beams. “It’s kind of like a bomb shelter,” Prigozhin jokes.

The basement lab space includes a newly renovated microscope room with metal mesh embedded in the floor tiles to eliminate static electricity from scraping shoe soles. “The facilities here are truly superb. We are very fortunate,” Prigozhin says. “And I couldn’t have asked for better neighbors. We are right next to Jeff Lichtman and Xiaowei Zhuang here in Northwest’s B4.”

Prigozhin’s first several months at Harvard will be spent setting up the lab infrastructure, building microscopes, and recruiting trainees. “Biophysics is a very eclectic field. On one day a member of my lab will be building a microscope, and another day she’ll be culturing cells and synthesizing nanoparticles, and, on another day, writing software,” Prigozhin says “You never get bored in biophysics.”

“It is unreal when a graduate student comes to you and says, ‘Hey, your research is cool! Can I do a rotation in your lab?’, because they have the entire Harvard University full of amazing labs to choose from,” he adds. “I’ve been fortunate to have supportive mentors. I am excited to pay it forward.”

Max PrigozhinPrigozhin Lab


by Diana Crow

Max Prigozhin

Max Prigozhin