Measurements of Electrical Characteristics of Mammalian Oocytes

The article describes the development of cell engineering technologies that use various electroporation modes and require knowledge of the electrical characteristics of living cells. Usually, cells are taken from laboratory animals of the same species, and the question of specific features of electrical characteristics of living cells remains open. Using the method of pulsed conductometry in an electric field of increasing strength, the electrical characteristics (conductivity, strength) were measured during electroporation and electrical breakdown of oocytes membranes of the following mammalian species: Mus musculus (mouse), Oryctolagus cuniculus (rabbit), Sus scrofa (pig), Bos taurus (cow), and Homo sapiens (human). Mathematical analysis of the experimental dependences of the conductivity of mammalian oocytes based on polynomial approximation was performed. The electrical characteristics of oocytes were obtained based on the analysis of approximating polynomials for the presence of maximum curvature (membrane electrical breakdown) and inflection points and local extrema (the degree of reversible electroporation). Significant species differences in the measured electrical characteristics of the studied oocytes were established. The measurement results showed a significant species specificity of electrical characteristics, reflecting the different resistance of oocytes to electrical breakdown and the degree of reversible electroporation of membranes, which is probably associated with the peculiarities of the lipid composition of oocyte membranes, the integrity of the cytoskeleton structure, and the resistance of cells as a whole to the impact of a pulsed field. The results obtained can be used to implement various modes of electromanipulation with a living cell, i.e., electrotransfection of deoxyribonucleic acid (DNA), genes, electrofusion, as well as for point lysis of cells with a lost apoptosis mechanism.