Track-A-Worm is an automated single-worm tracker designed for extracting and quantifying detailed bending and locomotory behavior of C. elegans. It is rich in functionality, easy to set up, easy to use, and open in source code. The system uses standard hardware, including a stereomicroscope, a digital black/white camera, a motorized stage, and a PC computer installed with Windows 7 and Matlab (including Image Acquisition Toolbox, Image Processing Toolbox, Instrument Control Toolbox, and Signal Processing Toolbox). The software includes seven modules: Calibrate, Record, Playback, Batch Spline, Fit Spline, Analyze, and Batch Analyze. Track-A-Worm converts gray images into binary images followed by automatic head identification and placement of 13 markers along a deduced spline. It can extract and quantify a variety of parameters, including distance traveled, average speed, distance/time/speed of forward and backward locomotion, frequency and amplitude of dominant bends, overall bending activities measured as root mean square, and sum of all bends. It also plots worm travel path, bend trace, and bend frequency spectrum. All functionality is performed through graphical user interfaces.

To download the software, you must agree to the following license agreement:

  1. You will use the software only for research and non-profit purposes. No component may be taken out of context for other uses. The copyright is retained by the developers.
  2. You may not redistribute the software to another lab except any new files developed in your own lab.
  3. You will acknowledge Sijie J. Wang and the Wang lab by citing their paper on Track-A-Worm (PLoS ONE) in reports or publications containing data obtained with the software.
  4. The developers are under no obligation to provide technical support at this time.

Potential users may wish to evaluate the software using the sample image files, which were recorded from a wild-type worm at 15 frames/sec. for 3 sec. The recommended threshold for binarization is 80.

If you would like to share with the C. elegans research community any new features that you have added to Track-A-Worm or make suggestions for improvement, please contact Dr. Zhao-Wen Wang (Email:

Download v1.0

User Manual for v1.0

Tracker-A-Worm version 2.0 is now available with the following major improvements:

1. Automatic spline fitting can now be done accurately for all kinds of worm shapes except for some challenging omega-shapes. Many omega-shapes can also be resolved.

2.You can now configure TTL signals using the Record module to control external devices (e.g., laser generators). Up to 3 different devices may be controlled independently in any on-and-off patterns. This feature may be conveniently used for optogenetic stimulation.

3. A new module allows the quantification of worm curvatures at various positions along the body axis.

4. The ventral and dorsal sides of a worm can now be marked at the beginning of each recording. This feature is especially useful for detecting curvature differences between ventral and dorsal sides.

5. The number of frames that can be included in each recording is now very large. You can recorded for essentially as many frames as you wish.

6. The Fit Spline window can now be resized to match any monitor size.

Note: 1. The  hardware NI myDAQ (~$200, National Instruments) is required for generating the TTL signals. 2. The software has been tested with only Matlab2013a running in Windows 7 (64-bit). 3. Additional information about Track-A-Worm may be found at

Download v2.0

User Manual for v2.0

List of Major Parts

The parts listed below are used in our setup. If you wish to use a different motorized stage or camera, please refer to the User Manual for suggestions.

  1. Motorized stage (Optiscan ES111) with stage Controller (ES9XY), stage stand (H413), and universal specimen holder (H473)
    Manufacturer: Prior Scientific, Rockland, MA, USA
    Price: ~$7,500
  2. Black-and-white CCD camera (XCD-V60)
    Manufacturer: Sony
    Price: ~$700
  3. Zoom stereo microscope (SMZ-800) with 1X plan achromat objective, C-Dsd OCC diascopic stand, V-T photo adaptor, etc.
    Manufacturer: Nikon
    Price: ~$7,000

Software Updates

If you wish to be notified of future updates, please fill out the Software Updates Form.