Tracking sperm in three-dimensions

Biochem Biophys Res Commun. 2008 Aug 15;373(1):125-9. doi: 10.1016/j.bbrc.2008.05.189. Epub 2008 Jun 12.


Sperm motility, crucial for fertilization, has been mostly studied in two dimensions (2D) by recording their swimming trajectories near a flat surface. However, spermatozoa swim in three-dimensions (3D) to find eggs, with their speed being the main impediment to track them under realistic conditions. Here, we describe a novel method allowing 3D tracking and analysis of the trajectories of multiple free-swimming sperm. The system uses a piezo-electric device displacing a large focal distance objective mounted on a microscope to acquire 70 image stacks per second, each stack composed of 60 images that span a depth of 100 microm. With this method, 3D paths of multiple sperm in the same field could be visualized simultaneously during 1 s. Within the same sample we found that surface-confined sperm swam 25% slower, produced 3-fold fewer circular revolutions per second, and had trajectories of 134% greater radius of curvature than those sperm swimming freely in 3D.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Imaging, Three-Dimensional / instrumentation*
  • Imaging, Three-Dimensional / methods*
  • Male
  • Microscopy, Video
  • Sperm Motility*
  • Spermatozoa / cytology*
  • Spermatozoa / physiology*
  • Strongylocentrotus