New microscope with 5 nanometer resolution can reveal tiniest cell process

Researchers have succeeded in developing a microscope that offers a resolution better than five nanometers – which is five billionths of a meter.

For comparison, the imaging offered by the newly developed microscope is equal to the width of a hair split into 10,000 strands, according to the researchers who developed it.

The research team comprising members from the Universities of Göttingen and Oxford in collaboration with the University Medical Center Göttingen (UMG).

According to them, the high-resolution fluorescence microscope can reveal even the tiniest of cell processes, and it promises to offer much richer information.

The need for a high-resolution microscope

The researchers stated that several structures in cells are so small that only fragmented images can be obtained from the use of standard microscopes.

The resolution of standard microscopes begins at around 200 nanometers, and therefore it cannot show the fine tubes which form a scaffold in the human cells.

Similarly, the distance between two nerve cells or a nerve and muscle cell is only 10 to 50 nanometers, which is too small for conventional microscopes.

Simply put, the new microscope can capture even the tiniest cell structures as it has a resolution better than five nanometers.

The newly-developed instrument is called a fluorescence microscope, as its working relies on the single-molecule localization microscopy.

Under this, “individual fluorescent molecules in a sample are switched on and off and their individual positions are then determined very precisely,” according to a press release.

The entire structure of the sample can then be modeled from the positions of these molecules. The current process enables resolutions of around 10 to 20 nanometers.

Further developments

Professor Jörg Enderlein’s research group at the University of Göttingen’s Faculty of Physics has now been able to double this resolution again – with the help of a highly sensitive detector and special data analysis.

“This newly developed technology is a milestone in the field of high-resolution microscopy. It not only offers resolutions in the single-digit nanometer range, but it is also particularly cost-effective and easy to use compared to other methods,” Enderlein said .

The team of researchers has also developed an open-source software package for data processing in the course of publishing their findings. This will lead to the development being available to a large number of specialists in the future, which will come in very handy in research.

The new method and the details associated with the development of the microscope were published in the journal Nature Photonics .

In this study, researchers integrated a single-photon detector array into a confocal laser scanning microscope, enabling the combination of fluorescence-lifetime single-molecule localization microscopy with image scanning microscopy.

This unique combination delivers a twofold improvement in lateral localization accuracy for single-molecule localization microscopy (SMLM) and maintains its simplicity.

“Moreover, the addition of lifetime information from our confocal laser scanning microscope eliminates chromatic aberration, particularly crucial for achieving few-nanometer resolution in SMLM,” said researchers in the study .

The approach, named fluorescence-lifetime image scanning microscopy SMLM, was demonstrated through direct stochastic optical reconstruction microscopy and DNA point accumulation for imaging in nanoscale topography experiments on fluorescently labeled cells, showcasing both resolution enhancement and fluorescence-lifetime multiplexing capabilities.