A novel method of sperm selection and separation
In the previous 2 articles, we have explained why the selection and separation of sperm is important and some of the various methods used to perform this important procedure.
Now, we would like to introduce a novel method by which optimum selection, separation and isolation of sperm is carried out. This is by Electrophoresis which has been described as “the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric field”. This method separates and isolates high quality sperm cells based on their morphology, motility and net negative charge (more electrons than protons).
A prototype electrophoretic device was developed for sperm separation and isolation. In preliminary clinical trials, it was shown to support normal embryo development and fertilization. Hence, based on the positive results, another electrophoretic sperm isolation device known as the Felix™ system has been developed for commercial use and is being evaluated in many clinical trials all over the world.
Andrology Center, Coimbatore was part of this study (with a paper published) carried out by many international ART centres in 5 countries – Australia, Sweden, India, the USA and China to compare the quality of the spermatazoa isolated by DGC and Felix™. These studies took into consideration the time for processing the samples, the concentration, motility and vitality of the sperm and the DNA integrity. In all the centres, the details of motility and percentage of immotile cells were analysed according to the WHO criteria for examination and processing of human semen.
The DNA integrity tests were carried out by using 3 methods – SCSA (sperm chromatin structure assay), – India and China, HALO (a sperm chromatin dispersion assay) – Australia and Sweden – and TUNEL (Terminal dUTP Nick-End Labeling) – USA.
Volume: The results showed not much difference in the measurement of semen volumes. Sperm concentration varied significantly, with the sperm numbers higher in Australia than in India and China. The progressive motility also varied, with the China and American datasets showing lower levels of progressive motility than India and Australia. Contrastingly, non-progressive motility was low in all centres. China and USA had higher levels of motility.
Sperm isolation was found to be improved with both Felix™ and DGC, where spermatozoa with higher levels of vitality and total (progressive and non-progressive) motility were found. The DGC did recover more spermatozoa. However, the amount collected by Felix™ was sufficient for IVF and ICSI treatments.
DNA damage: The SCSA analysis showed a great difference between the 2 methods. The Felix™ system was able to isolate sperm cells with less DNA damage than the DGC isolation method. This was also confirmed with the TUNEL method.
Time is important and the standardised Felix™ method takes just 6 minutes to complete the process, while DGC takes much longer, which can have a negative impact on the sperm. The quality of DNA observed with the Felix™ technique was far advanced from DGC.
Overall, this new device of the Felix™ system for sperm selection is a step in the right direction, especially since ART (Artificial Reproductive Technologies) is increasing in popularity and requires the best method in separating and selecting sperm for its treatment setting.
Andrology Center is the only licensed laboratory to carry out the genuine SCSA test in India. With the new techniques and state of art equipment, accurate results are guaranteed which, in turn, are mutually beneficial to the physician and the patient for treatment.
