Multicolor Electron Microscopy Reveals Proteins And Cell Architecture At Nanoscale Resolution

Scientists person developed a caller imaging method that uses a caller opposition system successful bioimaging to merge nan strengths of 2 powerful microscopy methods, allowing researchers to spot some nan intricate architecture of cells and nan circumstantial locations of proteins-all successful vivid colour and astatine nanometer resolution.

The breakthrough, called multicolor particle microscopy, addresses a longstanding situation successful biologic imaging: scientists person traditionally had to take betwixt seeing good structural specifications aliases search circumstantial molecules, but not some astatine once.

The attack opens doors for studying everything from cell signaling to nan statement of molecular clusters wrong cells, each while seeing precisely wherever these processes hap wrong nan cell's architecture. The investigation will beryllium presented astatine nan 70th Biophysical Society Annual Meeting successful San Francisco from February 21–25, 2026.

I've ever been fascinated by processing caller microscopy techniques that tin image things we haven't seen before. We're building a multicolor particle microscope-a method that combines nan benefits of particle microscopy and fluorescence microscopy."

Debsankar Saha Roy, a postdoctoral chap successful nan laboratory of Maxim Prigozhin astatine Harvard University

Traditional fluorescence microscopy useful by attaching glowing tags to proteins of interest, past sparkling visible ray connected nan sample to make those tags ray up. This attack is fantabulous for locating circumstantial molecules, but it has important limitations. "The solution is constricted to astir 250 to 300 nanometers, truthful you can't spot individual proteins clearly," Roy explained. "But nan bigger rumor is that you don't spot nan building of nan cell. You spot immoderate is labeled, but you don't spot everything other astir it."

Electron microscopy, connected nan different hand, tin uncover cellular structures successful exquisite detail-down to a fewer nanometers-but hasn't traditionally been capable to place circumstantial molecules successful color. Scientists person tried combining nan 2 approaches by taking abstracted images pinch each method and past overlaying them, but aligning nan images precisely, particularly successful ample samples for illustration encephalon tissue, has proven highly difficult.

The Harvard team's solution is elegant: alternatively of utilizing 2 abstracted imaging sessions, they usage a azygous particle beam to execute some tasks simultaneously.

"We're not sending successful light-we're sending an particle beam," Roy said. "We person probes that you tin connect to a macromolecule that emit visible ray erstwhile excited by electrons. This process is called cathodoluminescence. So from nan aforesaid particle beam, you get 2 sets of information: nan colored awesome from nan probes, and besides nan elaborate structural image from nan electrons."

A cardinal advantage of nan method is that researchers tin usage existing fluorescent dyes that are already wide disposable and well-characterized. The squad had antecedently developed lanthanide nanoparticles arsenic probes for muticolor particle microscopy, and moving to connect them to proteins.

More recently, nan squad made a astonishing find erstwhile they placed immoderate communal fluorescent dyes successful nan particle microscope. "The astir astonishing point we observed was that modular dyes utilized successful fluorescence microscopy besides emit visible ray erstwhile you excite them pinch electrons," Roy said. "That had ne'er been seen before. And these dyes-and their macromolecule labelling methods-are already developed and available; you don't person to create thing new."

The squad has already demonstrated nan method useful successful mammalian cells and biologic tissues, including fungus-infected flies.

Looking ahead, nan researchers purpose to widen nan method into 3 dimensions. Currently, nan method produces flat, two-dimensional images. The adjacent frontier is adapting it for usage pinch cryo-electron microscopy-a method wherever samples are flash-frozen, preserving cells successful their earthy authorities and allowing scientists to image them from aggregate angles to build 3D reconstructions.

"We want to widen this multicolor particle microscopy attack to 3D," Roy said. "To get there, we purpose to instrumentality this method successful ultrathin sections of compartment embedded matrices and/or successful cryo-electron microscopy-that's nan adjacent step."