Modification of the CRISPR-Cas9 system by introducing deactivated Cas9 endonuclease (dCas9) and binding the catalytic domains of epigenetic modifiers and/or transcriptional repressors and activators to it, enabled targeted manipulation of the epigenome and gene expression. The use of the dCas9 orthologs and multiple sgRNAs allows simultaneous manipulation of multiple different genes and/or epigenetic marks. The fusion of the catalytic domain of the TET1 (Ten-eleven translocation) enzyme with dCas9 allows targeted DNA demethylation resulting in an increase in gene expression, while the fusion of the VPR transcriptional activator with dCas9 directly affects gene activation. The aim of this study was to design assays for DNA methylation analysis by bisulfite pyrosequencing that would analyze methylation at CpG sites located upstream and downstream of the regulatory region of the HNF1A gene targeted by TET1-dSaCas9 and VPR-dSpCas9 fusion proteins in HEK293 cells. I have shown that there is a decrease in the degree of methylation in CpG sites located upstream and downstream of the target region after the transfection of cells with TET1-dSaCas9 fusion and double transfection with TET1-dSaCas9 and VPR-dSpCas9 fusions. By using a quantitative PCR method, I have found that TET1-dSaCas9 and VPR-dSpCas9 caused an increase in the transcriptional activity of the HNF1A gene and their joint action induced a long-lasting effect on transcriptional activity.