The most important thing is the quality of the semen sample, which we get from the patients on the day of fertilization. According to the quality of the sample, we can choose one of the four main researching methods which we have in our lab. Some of them are focused on sperm where we have more than a thousand million per millilitre like Fertile chip and MACS. Every research method has some logic behind it. Fertile chip system or like pre-selection method is focused on the motility of the sperm. When we conceive naturally – only the sperm with the best motility can get to the oocyte. The second method is MACS system, but again to use this, we need to have good quality sperm and many sperm in the sample. It is focused on dividing the sperm, which are design to apoptosis in the body because the body itself has few systems on how they can solve or see if the cells inside are good or bad. We have these systems, like all human.
One of the systems is phosphatidylserine system which can be marked like the bad quality cells or sperm as well, but white cells can be somehow checked, and if they are not good enough – the white cells will make some extra mark on this cell.
This mark is a small molecule of phosphatidylserine, and then other white cells which are going through the body, they are looking for some cells which are not good enough. When they see the cell marked with phosphatidylserine, it will destroy it.
This system can be applied on the semen sample, and we can divide the ones with phosphatidylserine mark on it, and they can be put away. So only the sperm without this mark will be used for the fertilization process – this is the MACS system. There are two more systems methods, which can be used even with a lower quality of semen, a small number of sperm in the semen sample. One of them is called PICSI method, it is focused on the maturity of each sperm, and it can be done on a 100 sperm. PICSI method works with a drop of hyaluronic acid, which is quite a common molecule in our bodies. In the fertilization process, the surrounding cells of the oocytes are also covered in hyaluronic acid.
In normal fertilization, the sperm has to be attached to the hyaluronic acid for the process of capacitation and then across embryo reaction and, when the sperm doesn’t have this receptor ready for the attachments to the hyaluronic acid, this sperm
cannot fertilize the oocytes at all. This method can show which sperm has this receptor, and this can be then used for fertilization. But nothing is optimal in life, and there can be mistakes. Sometimes we can see that on this hyaluronic acid there is also the sperm that doesn’t look very well. In general, if the receptor is there, the sperm should be fine, but as I said nothing is hundred-per cent. This might be my least favourite method, but someone else might have good results, so we do offer it as well.
The last method offered to patients is IMSI, which is focused on the morphology of each sperm. We can magnificate the sperm up to the 6000 more than normal which can allow us to see the inner quality of the cytoplasm in the head of the sperm, and we can see some problems in the shape of the head, some morphology issues in the neck, in the tail etc. When we have many sperms, and some of them have morphological problems, we can choose the best-looking sperm. If the sperm looks how it should look, hopefully, the DNA will be fine as well.
Unfortunately, none of these methods can show us the genetic information itself. And it is the most important thing, but there is no method now in the field that can show us the genetic information and not destroy the sperm. Hopefully, in the future, a better method will be developed.