Biophysical Society Thematic Meeting | Tutzing 2026

Single-Molecule FRET: The Next 30 Years

Tuesday Speaker Abstracts

FROM STRUCTURE TO OBSERVABLES: OPTIMAL DYE MODELS FOR PREDICTING LIFETIMES, ANISOTROPIES, AND FRET Thomas-Otavio Peulen 1 ; Daria Maksutova 1 ; Thorben Cordes 1 ; 1 TU Dortmund, Physical Chemistry, Dortmund, Germany Structure-based first-principles prediction of fluorescence lifetimes, anisotropies, and FRET observables remains challenging, as the intricate interactions between a fluorophore and its local environment must be accurately described over a broad range of spatial and temporal scales. These interactions include dye-linker dynamics, steric constraints, local electrostatics, solvent accessibility, quenching processes, and orientational fluctuations, all of which can strongly influence the observed photophysical behavior. The photophysical behavior of fluorophores can be predicted using spectroscopic dye models. Here, we present principles for optimizing dye representations through the integration of experimental observables and molecular modeling. By systematically incorporating experimental information, dye representations can be refined to provide more accurate predictions of fluorescence lifetimes, anisotropies, quenching, and FRET observables. Here, we present principles for the optimization of spectroscopic dye representations using a Bayesian framework that integrates molecular dynamics simulations and experimental data obtained from free dyes, dye-labeled proteins, and nucleic acids. This integrative approach enables the systematic refinement of dye models to increase the accuracy of structure-based fluorescence observables predictions. The resulting refined dye models are applied to a broad range of fluorophores, ranging from small organic fluorophores covalently attached to biomolecules and measured in vitro to fluorescent proteins studied in living cells. The dye-model refinement approach improves the accuracy with which fluorescence observables to relate molecular structures and dynamics.

SM-FRET IN INDUSTRY - A 35-YEAR JOURNEY Rainer Erdmann 1 ; Evangelos Sisamakis 1 ; Felix Koberling 1 ; 1 PicoQuant GmbH, Berlin, Germany

PicoQuant and its scientific predecessors have been active in the field of time-resolved and highly sensitive fluorescence detection for more than 35 years. From the very beginning, this work e.g. has been very closely linked to the work of Claus Seidel. PET and FRET already played a role in the ‘4 dyes – 1 lane’ approach to realising time-resolved DNA sequencing in the early 1990-ies. PicoQuant was founded in 1996 with the aim of making complex scientific methods and equipment accessible to a wide range of research groups in a simple and robust manner. The first part of the presentation will focus on the successful close collaboration with leading scientific research groups and the microscopes that have resulted from this. We will then present the latest results from our collaborations in the fields of FLIM, FCS and FRET highlighting the benefits of modern SPAD arrays.

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