Magnetic activated cell sorting (MACS) is a new technique that allows us to distinguish spermatozoa with high DNA fragmentation levels – 30% or higher – from the not fragmentized ones.
Magnetic sperm separation refers to a method of processing sperm based on their potential for surviving.
When the genetic material (DNA) in a cell has gone through some damage, it becomes fragmented initiating a process of self-destruction (programmed cell death or apoptosis in scientific terms). Sperms that have lost their genetic integrity exhibit DNA fragmentation and therefore, they start a process of self-death. These dying sperms will appear normal for a while, and if selected during sperm processing for usage with an ART, they may proceed to successful insemination. However, as their DNA is irreversibly damaged, the development of an early embryo will be halted and unsuccessful.
For magnetic sperm separation, we use a technique known as Magnetic-Activated Cell Sorting (MACS). This technique makes use of very small magnetic spheres (microspheres) that bind to the damaged self-destructive sperms, and a magnet for separating them from the unbound healthy sperms.
Magnetic sperm separation is done with MACS and it is performed by one of our andrology technologists in the laboratory following sperm collection for fertility treatment.
Following from a standard sperm wash and density-gradient sperm separation procedure, sperms are mixed with magnetic microspheres coated with a highly specific antibody (Annexin V) that can only recognize and bind an antigen (phosphatidyl serine) located on the surface of dying sperms. After 15-20 minutes of incubation, the mixture of microspheres and sperms is loaded through a magnetic-field column. As a result, the dying sperms bound to the magnetic microspheres become trapped, and the healthy ones pass through the column. After a final centrifugation step, high-grade quality sperms are isolated and re-suspended in a medium for usage with an ART. Sperm isolation with MACS may take up to half hour.
We also apply MACS after sperm freezing in order to select sperms that have not been affected by the cryopreservation / thawing process before being used in an ART.
Every man undergoing fertility treatment and ART can benefit from these methods. They are designed for the identification and isolation of the best-quality sperm out of the semen, aiming at a successful artificial insemination or IVF.
The method of choice after initial semen wash and assessment of your sperm depends on your individual circumstances, semen analysis, health and fertility history.
The swim-up method tends to be used with samples that have a high percentage of motile sperms.
The density-gradient sperm separation method has been used routinely, as it is efficient with a wide range of semen quality. This method can also be used with azoospermia (absence of sperm from semen), after a testicular sperm recovery (for instance after TEsticular Sperm Extraction, TESE, or Percutaneous Epididymal Sperm Aspiration, PESA), or for cases of retrograde ejaculation.
Magnetic sperm separation with MACS, on the other hand, is only used in conjunction with density-gradient sperm separation, when there is speculation that your semen may contain sperm with a high percentage of DNA fragmentation. For instance, if you have been a smoker or your work exposes you to pollution or toxic materials.
MACS will also be used when you have experienced a previous unsuccessful ART, unexplained infertility (cases for which we cannot find / define the cause(s) of inability to conceive naturally), or repeated miscarriages, and no other causative factors apart from a high DNA fragmentation index (DNA fragmentation test) have been found.
How do sperm improvement methods contribute in the success of ARTs?
Sperm improvement methods aim to select the most optimum samples for ART minimizing the risk of abnormal sperms being used.
With the improvement of the density-gradient sperm separation over the years, sperm isolation and separation has become very efficient. This method is relatively quick and can be combined with magnetic sperm separation, without the overall processing time affecting the quality of the isolated sperms.
Further, the use of magnetic sperm separation has greatly increased the chances for a successful ART, especially in couples that have previously experienced a failed attempt due to high DNA fragmentation in sperm.
If the sperm improvement method used for your case was not successful with an ART, here at AAFC, our specialist doctors will provide you with a comprehensive consultation for all other available / applicable options, and with explanations, where possible, for the reasons behind a negative outcome.
Sperm improvement methods aim to select the most optimum samples for ART minimizing the risk of abnormal sperms being used.
With the improvement of the density-gradient sperm separation over the years, sperm isolation and separation has become very efficient. This method is relatively quick and can be combined with magnetic sperm separation, without the overall processing time affecting the quality of the isolated sperms.
Further, the use of magnetic sperm separation has greatly increased the chances for a successful ART, especially in couples that have previously experienced a failed attempt due to high DNA fragmentation in sperm.
If the sperm improvement method used for your case was not successful with an ART, here at AAFC, our specialist doctors will provide you with a comprehensive consultation for all other available / applicable options, and with explanations, where possible, for the reasons behind a negative outcome.