The “3D Live‑Cell Nanoscopy” consortium, funded under the KMU‑innovativ: Photonics/Optical Technologies programme, ran from 1 February 2017 to 31 July 2023. The partners were Abberior GmbH, Abberior Instruments GmbH and the Max‑Planck Institute for Biophysical Chemistry. The project’s core aim was to create fluorophores that are compatible with the highest‑resolution single‑molecule techniques, particularly MINFLUX and STED, and to develop suitable labeling strategies for live‑cell imaging.

A central technical outcome was the design of a new class of rhodamine‑based dyes that can switch between a closed, non‑fluorescent state and an open, fluorescent state. The closed form is cell‑permeable, allowing the dye to cross membranes without carrying a charge, while binding to a target shifts the equilibrium toward the open, bright state. This switchable behaviour provides a high contrast ratio between unbound and bound dye, a critical parameter for MINFLUX where only a few fluorophores may be active at any time. The dyes were engineered to be small, compact, and compatible with both polar and non‑polar environments, ensuring efficient uptake in living cells. Over 20 new fluorophores and probes were synthesized, covering both green and red emission bands, and more than 30 existing dyes were evaluated for suitability in MINFLUX and STED workflows.

The developed fluorophores were tested on a range of biological specimens. Cell‑biological test samples with known architecture, such as the nuclear pore complex of mammalian cells, were prepared in collaboration with scientists from the European Molecular Biology Laboratory. Additional studies examined protein organization within mitochondria and peroxisomes, while an external partner, the University Hospital Hamburg‑Eppendorf, provided samples of bacterial membrane‑protein complexes. These experiments demonstrated that the dyes enable high‑resolution imaging on the MINFLUX demonstrator and on conventional microscopes, and that they can be used for both fixed and live‑cell samples. The results were published in the peer‑reviewed journal Methods and Applications in Fluorescence (Carsten A et al., 2022) and contributed to the broader literature on MINFLUX and super‑resolution microscopy.

Beyond the scientific achievements, the project laid the groundwork for future commercialization. After the project’s conclusion, a six‑month follow‑up phase will refine the dyes and embedding media for market readiness. The plan is to launch the first products within nine to twelve months, targeting a price range of €500–€700 per reagent. With an estimated first‑year sales volume of 200–400 units, projected revenue is €250 000, rising to about €1 million five years after launch. The dyes’ compatibility with other single‑molecule techniques such as PALM, GSDIM, and STORM expands the potential customer base, allowing Abberior to broaden its market without cannibalizing its existing STED and conventional fluorescence product lines. The consortium’s collaborative framework—combining synthetic chemistry, photophysics, and cell‑biological validation—has produced a robust portfolio of fluorophores poised to advance live‑cell nanoscopy worldwide.