The Huygens Object Stabilizer

This brand new tool can measure and correct for cell motion, thermal drift, shaking, and other types of movement (x-y-z translation and axial rotation). Both the measurement and subsequent stabilization are done in 3D and at sub-pixel level. The Stabilizer not only stabilizes 2D or 3D time series, but it also allows the alignment of slices within a 3D stack.

The Object Stabilizer can be found in the Analysis menu in Huygens Essential and Professional.

Images show the sum of four time frames of an apoptotic cell stained with fluorescent H2B nuclear protein. Time interval between slices is 300 seconds. Courtesy of M. Varecha and M. Kozubek, Masaryk University, Czech Republic.

Stabilization of time series

Stabilization over time works best if the time series has been deconvolved first.

For time series there are three stabilization methods available:

• Cross correlation. This can be considered an 'all-round method'. It can correct for both x-y-z translation and axial rotation. Adjacent time frames are compared and the program tries to find the best alignment by maximizing overlap.
• Multi object tracking. When your image contains well-defined objects, i.e. nuclei or small particles, then the image may be stabilized using object tracking. Objects are tracked over time and their average movement is used to stabilize the time series.
• Center of mass alignment. This method works best if the image contains a single large object. No objects should cross the image borders, and the contrast between object and background should be high.

Alignment of slices in 3D stacks (no time series)

3D alignment can be applied prior to deconvolution. The Object Stabilizer may improve the deconvolution of 3D stacks that suffer from severe misalignment between adjacent slices.

Extra features for the near future

These features will be available in the near future:

• Automatically cut out multiple moving objects.
• Filtering of the stabilization coordinates and tracks.
• Export stabilization data to text file.
• Export of individual object tracks to text file.