Sperm selection techniques

The MACS and FERTILE techniques select the spermatozoa with the best characteristics, thus increasing the possibility of pregnancy.   


Sperm DNA fragmentation, as the name suggests, refers to lesions in the genetic material of the spermatozoon. For a spermatozoon to have good fertile potential, it must contain genetic material that is in good condition at the time of fertilization.

The use of MACS and FERTILE techniques has the objective of increasing the probabilities of fertilization and pregnancy by selecting the best spermatozoa to be used in the different reproduction techniques.

MACS and FERTILE sperm selection techniques

  • DNA fragmentation studies over 15%.
  • Men who have received chemo or radiation treatments, altered FISH.
  • Severe seminal alterations.
  • Men with testicular varicoceles
  • Repeat abortions.
  • Sterility of unknown origin.
  • Failed IVF
  • Men with advanced age.
  • Men with toxic habits (tobacco, alcohol …)

Magnetic-Activated Cell Sorting (MACS) 

What is the MACS process?     

MACS is a technique based on the immunomagnetic separation of spermatozoa that selects those with the best characteristics to be used in assisted reproduction techniques.

This technique allows for the elimination of damaged spermatozoa, thus improving their capacity for fertilization and increasing the probability of giving rise to an evolutionary gestation.


Fragmented or degenerated sperm naturally enter a process of apoptosis (programmed cell death).

Immunomagnetic separation is based on this process to separate the spermatozoa with better characteristics from those in apoptosis. Thus, a protein called adnexin-V (attached to a magnetic particle) recognizes and binds to the apoptotic spermatozoa and separates them from the rest.

The sperm sample is placed in a column which, thanks to a magnet, will retain the damaged spermatozoa that are attached to the V-anexin (and this time attached to a magnetic particle).

The spermatozoa that are able to pass through this column and not join the V-annexin will be the healthy spermatozoa, with complete DNA (spermatozoa with the greatest chances of being genetically normal), and therefore, these will be the ones that we will use in the different assisted reproduction techniques (Artificial Insemination (AI), Conventional In Vitro Fertilization and ICSI).


What is the FERTILE process? 

The FERTILE chip is a device that allows the selection of the best spermatozoa through the microfluidic technique. This technique imitates the conditions of the female vaginal tract to select the quantity and integrity of the spermatozoa that reach the egg, thus increasing the chances of fertilization and pregnancy.


The freshly ejaculated sperm sample is placed in the entrance well of the microfluidic chamber and allowed to incubate for a short time. During this time, the sperm must pass through the microfluidic channels until they reach the exit well. The sperm that make it to the exit well will be the ones that we will use later in the Intracytoplasmic Sperm Injection (ICSI).

The sperm selected with the FERTILE® chip show a better mobility, morphology, low DNA fragmentation rates and less Reactive Oxygen Species (ROS), thus increasing the probability of pregnancy.



It’s quite simple. All you have to do is contact Embriogyn and make an appointment with our specialists at the time that suits you best. In case you can’t come in person to the clinic, visits can also be arranged via Skype.