Immunoglobulin G (IgG) contains a light and a heavy chain. The biological activity of IgGs is modulated by the N-glycosylation to the fragment crystallizable part. For the research of the glycosylation profile IgGs and glycoengineering technology, it is used HEK 293 Freestyle cell line. The 293 cells grow in a suspension culture, it is easy to transfect them and they excrete IgG in the medium, if we have transfected them with expression system for heavy and light chain of IgGs. Transfecting cells with plasmid vector carrying the heavy chain, the light chain and molecular tools that affect the regulation of glycosylation, such as an activator or repressor of transcription based on CRISPR-Cas9 system, this model allows the research of glycosylation IgG. The aim of this study was to construct vectors for simultaneous expression of a heavy and a light chain of IgGs by using two different approaches for designing expression vectors. The first approach is based on bicistronic expression of the heavy and the light chain of IgGs concatenated with 2A self-processing peptide. The second construct contains two expression cassettes consisting of two promotors that drive the expression of the heavy and the light chain. HEK293Freestyle cells were transfected and compared by a dot blot analysis, considering the amount of the excreted IgGs. Constructs for production IgGs with T2A self-processing peptide were successfully assembled. For plasmid constructs cloning the bacterial strain E. coli XL10‐Gold was used. The vectors were transfected into HEK293 Freestyle cell line. Supernatant was collected the third and fifth day post-transfection for semi-quantitative analysis IgGs expression with dot blot method. The system with two expression cassettes (for heavy and light chain) consisting of two promotors wasn´t obtained. Possible cause is repetitive sequences which is associated with increased frequency of recombination in E.coli XL10-Gold.