Photo-Switchable Cyanine Dyes for Super-Resolution Microscopy

• Applicant: Dr. Virginia Wycisk
• Subject Area: Organic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2018 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 411742491

Super-resolution microscopy offers the unique opportunity to investigate cellular processes in living organisms. To ensure the acquisition of high resolution images, photoactivatable dyes are required which can be turned from dark (OFF) to highly emissive (ON) states by irradiation with light. To date, photoswitchable proteins are frequently used, but broader utilisation for super-resolution microscopy becomes limited by their low photostability and costly production from genetic material. Furthermore, this strategy cannot be used to label endogenous proteins. In contrast, the use of synthetic molecular switches remains under-explored. Several designs of organic dyes have been invented, but most of them require ultraviolet irradiation to induce the switching process, which is a critical aspect for live cell imaging. My research project therefore focuses on the development of new photoswitchable dyes which are highly photostable and switchable with visible light. From previous studies that were performed at the Freie Universität Berlin, I could gain extended knowledge on the synthesis of cyanine dyes and chemical tuning of their optical properties. Further investigations confirmed their suitability as dye labels for live cell imaging. Together with the group of Professor Anderson (Oxford, UK) I will further develop cyanine dyes into custom-built molecular photoswitches with optimised photophysical properties for high-resolution microscopy. This project will build on my existing expertise on chemical tuning of cyanine dyes and will be combined with the expertise on photoswitchable dyes of the Anderson Laboratory (Oxford, UK). Taken together, I will explore the potential of photoswitchable cyanine dyes for super-resolution microscopy of living cells, thus contributing towards a better understanding of living systems.

• DFG Programme: Research Fellowships
• International Connection: United Kingdom
• Host: Professor Harry Anderson, Ph.D.