4D tracking

Sperm cells have a chiral memory

Fertilization is the culmination of a complex selection of the single fertilizing sperm from among the millions delivered in the mammalian ejaculate. That selection imposes challenging barriers in the female reproductive tract opposed by swimming behavior of sperm that allows a small number to reach the site of fertilization. DHM® is used in this publication to investigate the flagellar waveform and sperm swimming behavior.

Unique advantages of Lyncée Tec DHM®

Material and methods

  • Biological Model: mice, bovine, and human sperms collected under approved ethical protocols.
  • DHM®: T1000, 10x/0.3 NA, 20x/0.4 NA and 40x/0.6 NA objectives.
  • Data analysis: Visualization of the sperm flagellum in 4D used a custom-designed Spyder script by Lyncée Tec SA. Visualization of sperm swimming trajectories in 4D used the Gizmo function of IgorPro. IgorPro functions also produced Procrustes alignments and visualization of path trajectories in polar coordinate


DHM®  gives new quantitative insights into both the flagella waveform and the swimming behavior of sperm. New areas have been opened for exploration of how sperm generate, store, and reuse the torsional forces that underlie the flagellar waveform.


Four-dimensional analysis by high-speed holographic imaging reveals a chiral memory of sperm flagella, PLOS ONE, Published: June 28, 2018

Michael Muschol, Caroline Wenders and Gunther Wennemuth

The sperm flagellum in 4D as shown in an animation of the 3D projection (blue trace) and its projections onto the XY, XZ, and YZ planes. Sampling 100 Fps. The traveling waves of Z-plane excursions are easily seen. (Source PLOS ONE)

Lyncée Tec team provided us with a full system consisting of a DHM, incubation chamber and fluorescence module to easily acquire images of sperm cells without perturbing them.
The 4D tracking capability of the Lyncée Tec microscope allows us to study the 3D trajectories in time of sperm cells at an unprecedented speed of 194 images per second without scanning. In combination with other software tools we were able to use Lyncée Tec tracking software to extract the full 4D trajectories of the sperm cells in the field of view. This novel feature helps us observe the sperm cells specific behavior and correlate it with clinical conditions.
This unique system allowed us to enter a completely novel field of research in male reproduction.

Professor Gunther Wennemuth, Institute of Anatomy, Essen University Hospital, Germany
Animated trajectory of a free swimming bull sperm during a 2.5 sec sequence. A green ball locates the head of the sperm and the color code of the trajectory displays the z value. A green helix that follows the path and a projection on a polar coordinate system in the top left corner of the video point out the clockwise chirality of the path. (Source PLOS ONE)

Bacteria 4D-tracking

Motility is a fundamental characteristic of life. It is on the base of fundamental biological phenomena such as microbial grazing parasitic infection, inter-microbial communication, and animal reproduction. Motile microorganisms are therefore among the most important life-forms on earth, not only because of their abundance, but also their functions. The understanding of these propulsion mechanisms is essential to understand biological systems and to the design of artificial nanomachines. It has major impact on various fields ranging from life science and material science to environmental science. 

Unique advantages of Lyncée Tec DHM®

Material and methods

  • Biological Model: Vibrio coralliilyticus bacteria immerged in water
  • DHM® solution: DHM® T1000 with 4D-tracking software module
  • Measurement cell: 5 mm x 5 mm x 0.2 mm (LxWxH)


DHM® can detect and capture an active reorientation behavior in the bacteria (highlighted in red in the figure), demonstrating the capabilities of DHM® to track bacteria during sharp turns. Size and physiological status of micro-organism are measured quantitatively.

Vibrio coralliilyticus bacteria tracks. The colors represent the time during that section of the tracks. Two tracks (highlighted in red) capture an active reorientation behavior in the bacteria, demonstrating the capabilities of this approach to track bacteria also during sharp turns. Courtesy of Prof. Roman Stocker, Hydrodynamik und Grundwasser im Dept. Civil, Geomatic und Environmental Engineering, ETH Zürich.

“We have tried multiple other systems to track bacteria, and were very positively surprised by the ease of use and the near-immediate results we could obtain with the Lyncée solution”

Prof. Roman Stocker, Hydrodynamik und Grundwasser im Dept. Civil, Geomatic und Environmental Engineering, ETH Zürich.