Super-resolution microscopy: Getting even closer to the limit
Ralf Jungmann is interested in processes that take place within unbelievably tiny spatial dimensions. Jungmann holds a professorship in experimental physics at Ludwig-Maximilians-Universitaet (LMU) in Munich, and heads a research group in molecular imaging and bionanotechnology at the Max Planck Institute for Biochemistry (Martinsried), and focuses on extending the capabilities of optical microscopy. His goal is to visualize the molecular interactions that take place within individual cells. In order to monitor the protein networks involved in such processes, he uses short DNA strands covalently attached to various fluorescence markers as probes to locate target proteins bearing complementary DNA tags. By exploiting the sequence specificity and versatility of DNA hybridization, it is possible to image the distributions of large numbers of molecules in single cells at super-resolution. The combination of DNA sequences with different fluorescent compounds explains why the technique bears the name DNA-PAINT.