ИСТИНА

Although the cryopreservation methods of biomaterial are actively developing for spermatozoa, the percentage of preservation of viability after freezing-thawing remains low: 40-60%. One of the leading causes of cell damage during cryopreservation is the formation of extra- and intracellular ice crystals. Therefore, the aim of the work was to study the influence of various components and conditions of freezing on the process of crystal formation in cryoprotective media. In the experiments, using the calorimetry method, the dependences of the heat capacity on temperature for basic solutions were obtained. It was shown that the addition of sucrose reduces the area of heterogeneous nucleation, which makes it possible to increase the survival rate of cells during cryopreservation in the studied media. With the help of X-ray diffraction analysis, more than 400 solutions for cryopreservation of cells, differing in the concentrations of the main components, and more than 30 types of alternative methods for freezing cells, differing in the location of cryotubes with samples during freezing and the rate of lowering the samples over nitrogen vapor were studied. As a result, two main methods of freezing were selected as the most effective in terms of the size of ice crystals formed in solutions.