DC play a pivotal role in the regulation of immune responses and in maintaining tissue homeostasis at transplantation. The aim of this study was to optimize the protocol of electroporation pDNA encoding IL-10 into mouse bone marrow derived DC (BMDC) and determine the dependence of the electroporation efficiency on various parameters. METHODS: BM-DC was generated by cultivating mouse BM progenitors in the presence of GM-CSF and IL-4 in 6 days. Electroporation was performed in the OptiMem medium in ECM 830 Square Wave Electroporation System (BTX). Transfection efficiency and cell death, IL-10-positive cell count was determined by flow cytometry in the monocyte region on BDFacsVersa. The quantitative determination of IL-10 concentrations in conditioning medium from transfected cell was conducted using mouse IL-10 Quantikine ELISA Kit (R&D systems). Statistical data were processed using the GraphPadPrism 6.0 program. RESULTS: By used pDNA encoding GFP was determined the optimal condition for increasing the number of GFP-positive cells with minimal total cell death. It was shown the use conditioning and culturing medium with GM-CSF and IL-4 after electroporation leads to an increase in the number of GFP-positive cells to 50% with 95% viable cells. By used pDNA encoding IL-10 was shown a significant increase in the number of CD11c+IL-10+ DCs. The ELISA was shown the dose-dependent production of IL-10 in the electroporation of DC by different amounts of the pDNA. CONCLUTION: Electroporation pDNA into BM-DC is an effective approach for obtaining DC with transient expression of immunoregulatory proteins. The determination of secretory proteins proved more sensitive method of assessing the efficiency of electroporation in comparison with the determination of GFP-positive cells. This approach can be useful for modulation of various cells function in the cellular technologies of immunologic tolerance induction. This work was supported by RSF. Agreement №16-15-00086 (11.01.2016)