ABSTRACT
BACKGROUND: In the research of human embryonic stem cells, introducing exogenous molecules such as DNA into cells is a common research method, but the transfection efficiency is relatively low. It is crucial to answer the question of how to optimize the existing conditions to improve the transfection efficiency. OBJECTIVE: To compare the effects of two different passaging methods on H9 transfection efficiency, in order to optimize the conditions required for embryonic stem cell transfection. METHODS: Human embryonic stem cell lines H9 were cultured for 48 hours after small clone passaging or single-cell passaging. Lipofectamine 3000 was used to transfect pAdTrack-AKT1 fluorescent plasmid into human embryonic stem cells. After 2 days of transfection, the expression of fluorescent plasmids was observed by fluorescence microscope and the transfection efficiency was detected by flow cytometry. RT-qPCR and western blot were used to detect the mRNA and protein expression levels of AKT1 respectively. RESULTS AND CONCLUSION: Under the fluorescence microscopy, the number of cells expressing fluorescent plasmids in the single-cell passaging group was more than that in the small clone passaging group, and the flow cytometry analysis showed that the transfection efficiency of cells in the single-cell passaging group was (47.18±2.00)%, which was significantly higher than (19.52±0.86)% in the small clone passaging group (P < 0.01). RT-qPCR and western blot analysis showed that the expression levels of AKT1 mRNA and protein in the single-cell passaging group were significantly higher than those in the small clone passaging group (P < 0.01). These findings indicate that single-cell passaging can increase the contact area between cells and transfection reagent liposomes, and improve the transfection efficiency of human embryonic stem cells.