Under in-vivo conditions, potentially fertile spermatozoa are separated from immotile spermatozoa, cellular debris, and seminal plasma in the female tract by active migration through the cervical mucus.

Sperm quality also plays a very prominent role in achieving a pregnancy through ART, and a variety of procedures exist for selecting better quality sperm for egg fertilization, such as Density Gradient and Swim-up.

Tips and Tricks:


The ideal sperm separation technique should:

  • Be quick, easy and cost-effective.
  • Concentrate as many normal, motile spermatozoa as possible.
  • Separate out the morphologically abnormal, the immature and the senescent sperm.
  • Eliminate macrophages, leukocytes, cellular detritus, bacteria and virus particles.
  • Remove toxic or bioactive substances, including decapacitation factors and reactive oxygen species (ROS).
  • Select sperm with longer telomeres and eliminate sperm with DNA fragmentation.
  • The Differential Density Gradient Technique is a gentle method of separating sperm from semen and is accepted as the state-of-the-art technology by reproductive specialists and scientists.