SACHET: seeded contour tracking measures Rab conversion kinetics on individual endosomes in live cells

SACHET enables per-endosome tracking in live-cell spinning-disk projections, following all 37 Rab5-to-Rab7 conversions where TrackMate followed only one of seven marked events.

• Why it matters: Existing population trackers struggle with hollow, deforming endosomes that exchange coats and touch neighbors, limiting measurement of Rab conversion kinetics at the single-endosome level.
• What they did: The human-supervised Fiji tool SACHET uses seeded adaptive contour tracking to localize endosome centers to 10 nm on simulated ground truth and recover transition time constants and lags without bias.
• The result: In five cell lines, Rab conversion toggles like a digital switch within seconds to minutes, with kinetics differing between lines, enabling quantification of membrane morphology and protein exchange per endosome.

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