Within the two (out of three) project periods, work has proceeded as expected, on all the major components needed to reach the goals:
Prototypes of the MINFLUX-based, next-generation fluorescence super-resolution microscopy platform are on place, operating in the near-infrared (NIR) wavelength range, offering one order of magnitude higher spatial resolution than current state-of-the-art super-resolution microscopes in the same wavelength range.
New single photon avalanche detector (SPAD) arrays have been developed with enhanced sensitivity in the NIR, and protocols for integration of the SPAD arrays into the MINFLUX platform have been established, offering additional means to enhance resolution and supress background.
A pulsed, narrow-linewidth, multi-line laser prototype has been assembled for label-free cellular imaging. After software development and successful optical performance tests, fulfilling requirements of fast spectral and pulse-width tuning, laser prototypes have been integrated into the two microscope prototype systems in the project.
The operation of the microscope prototype platform has been extended beyond the visible, into the NIR range. Integration of SPAD arrays into the platform prototypes has been accomplished and the pulsed, narrow-linewidth, multi-line laser prototypes have been installed into the microscope platforms and demonstrated for label-free morphological and chemical imaging of bacteria and human cells.
To make NIR-MINFLUX imaging possible, a range of NIR fluorophores have been investigated with respect to their blinking/switching properties, photostability and brightness, all critical parameters for super-resolution microscopy. We have then established excitation, imaging and sample conditions allowing NIR MINFLUX imaging of proteins on bacteria and human cells with nanometer localization precision.
With the MINFLUX platform, we can now image spatial localization patterns of proteins in bacteria and host cells with a few nanometers resolution, both in the visible and in the NIR. Harnessed with a pulsed, narrow-linewidth, multi-line laser, we can also perform label-free morphological and chemical imaging of bacteria and host cells. With this platform at hand, we have this far identified new localization patterns for at least two proteins coupled to bacterial disease and expect to present overlaid morphological and chemical images within the next months. Next, by further addressing this lead application, and by offering access to one of the developed microscope systems to biomedical researchers outside of the project, we will pave the way for new means to understand, diagnose and prevent cellular diseases. At the same time, these efforts will provide a test bed for the prototypes developed in the project and facilitate their way to market.
