SPERMATOZOA III :



We know today the sperm quality can be dependent on the amount of damage to the sperm DNA or DNA fragmentation. Normaly, DNA is arranged in a double helix or ladder configuration with side rails and rungs. If the rungs are broken, then the ladder is unsteady and won’t function properly.
This variable is completely independent.of others sperm functions. But
 the degree of DNA fragmentation correlates very highly with the inability of the sperm to initiate a birth regardless of the technology used to fertilize the egg such as IUI, IVF or ICSI.
Sperm with high DNA fragmentation may fertilize an egg and embryo development stops before or after implantation. It may even initiate a pregnancy during some weeks.
By testing for sperm DNA fragmentation, many cases of formally “unexplained” infertility can now be explained.

There are several ways to test for sperm DNA fragmentation; the most widely used test is called the Sperm Chromatin Structure Assay (SCSA).
The sperm are then labeled with a Acridinl orange colored dye that only attaches to the ends of broken DNA within the sperm cell.
If the DNA is intact then no dye will attach to the sperm. A flow cytometer is used to analyze ten thousand sperm from the sample.). A computer counts the percentage of orange-labeled sperm and software allows calculating an index known as the DNA fragmentation Index (DFI).

DFI, Usuall values :
Very good pronostic : DFI : < 15 %
Good ponostic : DFI : 15 - 30 %
Bad pronostic : DFI : > 30 %

The causes of high DNA fragmentation are those same causes of male factor infertility that we have known about for years such as chemical/toxin exposure, heat exposure, varicocele, infection, age, smoking, testicular cancer, radiation, and anything that increases the free radical levels in the semen among a list of many other things. It is very important to understand that sperm DNA fragmentation can change with time and it can be improved in many cases.

Other main techniques :

TUNEL technique (terminal uridine nick end labeling)

SCD technique (sperm chromatin dispersion)
Halosperm screen Test*.
The characteristics of Halosperm make this kit a reasonable alternative to allow basic and clinical research on sperm DNA fragmentation in any basic laboratory around the world.