Import pictogram


from a wide range of tracking softwares, including a direct upload from Fiji/TrackMate.

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Analyze pictogram


Fit a kinetic model to the distribution of jump length. Take into account the finite depth of field.

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Export pictogram


Save your analyses to a variety of formats (plots, tables, editable files). Ready?

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Why Spot-On? (and kinetic modeling)

Single particle tracking (SPT) is often seen as less biased and model-dependent than indirect and bulk techniques such as Fluorescence Recovery After Photobleaching (FRAP) or Fluorescence Correlation Spectroscopy (FCS).

Nevertheless, SPT data is subject to a number of biases and uncertainties, which must be corrected for in order to obtain accurate estimates of subpopulations. Spot-On offers a set of guidelines to perform meaningful SPT experiments and provides a comprehensive, bias-aware, framework to analyze the resulting data.

Take the tutorial

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How does it work? See for yourself.

Spot-On fits a two-states or a three-states model to the empirical distribution of jump lengths obtained from a single particle tracking dataset. To do so, Spot-On takes into account a finite detection volume and biases against fast-moving particles. From that, Spot-On extracts kinetic parameters: diffusion coefficients, fraction bound.

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Principle of Spot-On: fit

Get started (in a nutshell)

To use Spot-On is straightforward, and Spot-On is fully documented. We have a step-by-step tutorial that details how to use Spot-On from scratch. In particular, the tutorial will guide you through:

  1. Uploading trajectories from a wide range of formats
  2. Perform a thorough quality-check of uploaded datasets
  3. Fit a kinetic model on the distribution of displacements
  4. The export of the fitted coefficients, raw data and high quality graphics

or .

Spot-On workflow

Please acknowledge Spot-On in your publications:

Robust model-based analysis of single-particle tracking experiments with Spot-On.

Hansen, A.S.*, Woringer, M.*, Grimm, J.B., Lavis, L.D., Tjian, R., and Darzacq, X.