Linear Assignment Tracking Toolbox
Cells move and divide as they grow under the microscope. This makes identifying and following an individual cell difficult.
To track an individual cell, I created a MATLAB toolbox which implements a tracking algorithm based on the Linear Assignment approach (Jaqaman et al. Nature Methods, 2008). Two classes are defined here:
LAPLinker implements the object tracking algorithm and
TrackArray implements a data structure to hold the resulting time-series data.
While this code is based on the original paper, several significant changes have been made:
- To solve the assignment problem, we used the Jonker-Volgenant algorithm (MATLAB implementation by Yi Cao). This algorithm allowed solutions to be found up to 10x faster compared to the Mukres algorihtm which was used in the original work.
- This code does not implement the full tracking algorithm in the original. Specifically, I omitted the gap closing, merging, and splitting step for simplicity.
- The code implements several custom metrics to identify cells, including using an overlap score, which is calculated based on the number of pixels in object masks. This approach worked much better than distance for cells which are non-motile.
- This code also identifies cell division using the same overlap score.
Code, compiled MATLAB toolboxes, and instructions can be found here.
- Jaqaman et al. Robust single-particle tracking in live-cell time-lapse sequences. Nature Methods, (2008).
This toolbox has been used in a number of publications, including
- Moore et al. Mechanical regulation of photosynthesis in cyanobacteria. Nature Microbiology 5, 757-767 (2020)
- Hill et al. Lifecycle of a cyanobacterial carboxysome. Science Advances 6, eaba1269 (2020)
- Lo et al. Single cell analysis reveals multiple requirements for zinc in the mammalian cell cycle. eLife 9, e51107 (2020)
- Connacher, Tay, and Ahn. Rear-polarized Wnt5a-receptor-actin-myosinpolarity (WRAMP) structures promote the speed and persistence of directional cell migration. Molecular Biology of the Cell 28, 1924-1936 (2017)