Tracking-free mean square displacement analysis of molecular dynamics.

Image-derived mean squared displacement (iMSD) quantifies spatiotemporal dynamics in living cells without tracking, extracting diffusion coefficients and confinement dimensions from fluorescence stacks.

• Why it matters: Single-particle tracking can fail in high-density or low signal-to-noise data because it needs object localization and trajectory linking.
• What they did: The protocol computes a spatiotemporal autocorrelation of fluorescence intensity fluctuations from time-lapse images, then Gaussian-fits the correlation peak variance to generate iMSD curves.
• The result: iMSD yields diffusion coefficients, anomalous exponents, confinement dimensions, and average moving-object size, distinguishing Brownian, superdiffusive, and confined motion across temporal scales.

AI summary of the abstract · may contain errors · not medical advice · read the paper.