Storing the sperm

This method of storing sperm (ejaculate), like cryopreservation, has become quite widespread in cryomedicine. It includes the addition of a special medium to the seminal fluid, and further freezing it with the use of liquid nitrogen vapors. Consider this method of preserving male germ cells in more detail and tell you which sperm is suitable for dilution and further storage.

How does cryopreservation increase the chances of fertilization?

With natural fertilization, the secret of the male sex glands is mixed partly with the cells of the epidermis, as a result, a certain change in the pH of the medium occurs, which leads to the destruction of the lipoprotein cover of spermatozoa, i.e. to their activation. Being in this condition, the lifespan of the reproductive cells is severely limited, which excludes their further use for IVF. That's why the cryopreservation method is used .

This technique significantly increases the shelf life of sperm, and allows:

• reduce the motor activity of spermatozoa;
• provides them with an additional source of energy;
• protects the germ cell membranes from destruction;
• prevents accumulation of toxic metabolic products;
• blocks the reproduction of microorganisms in the ejaculate.

What mediums are used to store semen?

In order to facilitate, the so-called process of crushing the ejaculate, necessary for the isolation of germ cells from it, pre-dilute the sperm. Special reagents are used.

To date, it is customary to use synthetic media for semen storage, each of which requires special conditions. Typically, this kind of environment consists of several components, usually at least three. So, in their structure it is possible to allocate sugar, most often and are used glucose and lactose, sodium citrate.

If we talk about specific chemical compounds that can be used as media for storing sperm, then among these can be called Tris-buffer, Trilon B, EDTA, Spermosan PPK.

Under what conditions are the ejaculate stored?

The technology of freezing and storing sperm requires adherence to a special cooling regime, as well as the use of special devices. In this case, the laboratory room itself must necessarily be equipped with devices that sterilize the air.

Before the ejaculate is collected, all necessary devices for cryopreservation, in particular all kinds of flasks, graduated cylinders, pipettes, paper filters are sterilized in a special cabinet, at a temperature of 130-150 degrees. Before the direct sampling procedure, they are placed in a special thermostat, which maintains a constant temperature of 37 degrees.

Once the male sperm sample is taken away, it is placed in a sterile flask. The storage temperature of the sperm should be constant. The cooling process is carried out in 2 stages.

On the first of them, the ejaculate is first placed in a cold room, in which the temperature is gradually lowered. As a rule, its value is -35 degrees. After this, deep freezing is carried out, immersing a special flask with sperm into liquid nitrogen. In this condition, the shelf life of sperm can reach several decades.

To use ejaculate, cryopreserved earlier, the vessel along with it is placed in warm water, where slow thawing takes place. After that, the used cryoprotectants are removed, by repeated reprecipitation of sperm on the centrifuge. After that, the seminal fluid itself is replaced with a nutrient medium into which the spermatozoa are subsequently placed.