Jumping to Conclusions: Reversible jump MCMC developed for change point detection in single molecule localisation microscopy

Description

Fluorescence Localisation Imaging with Photobleaching (FLImP; Iyer et. al., 2024) is used to study clustering of proteins on the cell membrane; a process linked to the development of cancers such as non-small cell lung cancer. FLImP relies on the sequential photobleaching of fluorescent molecules (fluorophores) bound to membrane proteins, producing staircase-like temporal intensity traces as fluorophores switch off one-by-one. However, fluorophores can also display complex photophysical behaviour, including short-lived ‘off’ states (blink-events) and longer-lived dark states, which introduce closely spaced change points that standard methods frequently fail to detect. Currently FLImP uses a heuristic, conservative approach with extensive filtering, often leaving only 1% of all collected data; an inefficiency which makes it unsuitable for clinical use in its current form. By considering the number and locations of these photobleach and ‘off’ state events as a change point problem, we can estimate the number of fluorophores active in each frame; information that, when combined with fluorophore point spread functions, enables spatial localisation and clustering analysis. We present a change point detection algorithm based on reversible jump Markov chain Monte Carlo (Green, 1995), introducing moves to account for short-lived events. Performance is benchmarked against state-of-the-art methods using a comprehensive simulation study and applied to experimental GATTAquant DNA ruler data, demonstrating improved accuracy and increased recovery of usable information for downstream analysis.

Iyer, R. Sumanth, et al. “Drug-resistant EGFR mutations promote lung cancer by stabilizing interfaces in ligand-free kinase-active EGFR oligomers.” Nature Communications 15 (2024): 2130

Green, Peter J. "Reversible jump Markov chain Monte Carlo computation and Bayesian model determination." Biometrika 82.4 (1995): 711-732.

Period	12 Nov 2025
Held at	RSS Northern Ireland Local Group, United Kingdom
Degree of Recognition	Regional