Analysis of Sperm DNA Fragmentation
Sperm DNA Fragmentation is the rupture or damage of the DNA strands of the sperm.
The more such damages, the lower the degree of integrity of the genetic material and the less chance of pregnancy.
Methods of detecting fragmentation of DNA of spermatozoa
How can DNA fragmentation of sperm be detected?
There are different methods of determining the levels of fragmentation. In our center, we use the TUNEL test, recommended by researchers for fragmentation of DNA.
What is the difference between different methods?
Most fragmentation tests, including the SCSA and SCD tests, measure potential damage and the tendency to DNA denaturation, and therefore have lower predictive ability. And vice versa, the TUNEL test measures actual damage and has a high predictive ability. Currently, the threshold value of the TUNEL test, separating the norm from pathology, is <15%.
During the TUNEL-test, sperm react with an enzyme and those spermatozoa, that have fragmented DNA, are colored (if the bright-field microscopy is used), or begin to glow with green light (if using the fluorescence method).
This test is recommended in the following cases:
- Idiopathic infertility (for an unidentified cause).
- After repeated unsuccessful attempts of IVF.
- In case of low embryo quality.
- In patients with miscarriage.
- Varicose veins of spermatic cord.
- Men over 45 years of age.
- Frozen sperm (to ensure that the frozen sample has an acceptable level of fragmentation).
- Increased body temperature in the last 3 months.