Researchers at the Max Planck Institute of Biochemistry and Ludwig Maximilian University of Munich have developed an innovative fluorescence microscopy technique named Resolution Enhancement by Sequential Imaging (RESI), achieving Ångström resolution. This breakthrough allows for unprecedented exploration of biological systems, facilitating detailed observation of cellular structures, such as DNA, RNA, proteins, and lipids, which are typically smaller than the limits of traditional microscopy. The technique is built on the DNA-PAINT method, which enhances resolution through unique DNA sequences that identify targets within the sample. By sequentially imaging separate targets—too close to be resolved by standard methods—RESI differentiates them, achieving spatial resolutions of 0.85 nm (8.5 Ångström) with an accuracy of 1 Ångström. This capability was showcased by examining the molecular interaction of the anti-CD20 antibody Rituximab, revealing receptor arrangements in cells under treatment. With its compatibility with standard fluorescence microscopes, RESI provides a significant advancement in biological research, closing the gap between structural techniques and broader cellular imaging. The findings highlight the potential for enhanced understanding of cellular mechanisms and disease treatment strategies, marking RESI as a transformative tool in super-resolution microscopy.
