Abstract: Objective To screen a better liposome agent for modRNA transfection and to explore the feasibility and efficiency of using it to transfect various cell types and express target proteins. Methods After modGFP was transfected into MEF cells with RNAiMax and MessageMax, the transfection efficiency and protein expression effects of the two transfection agents were detected and compared by fluorescence microscope and flow cytometry. The better liposome agent was chosen for modGFP transfection into various cell types, and the transfection and expression efficiency were measured using the same methods. Besides, the co-transfection of modGFP and modmCherry, and the nuclear transfection of modnGFP and modmTBX5 into MEF cells were observed by fluorescence microscope. Results After MEF cells were transfected with modGFP for 24 h, flow analysis showed that the transfection efficiency of MessageMax(83.33%±3.23%) was slightly higher than that of RNAi Max(78.77%±6.12%), but there was no statistical difference. However, both flow analysis and fluorescent images found that MessageMax had a higher efficiency of protein expression within 1 week after transfection, making it a better modRNA transfection reagent. MessageMax could efficiently transfect modGFP into 3T3 cells, Hela cells and MCF-7 cells, achieve co-translocation of modGFP and modmCherry, and achieve nuclear localization of intranuclear factors nGFP and mTBX5 in MEF cells. Conclusion Compared to RNAi Max, modRNA transfection with MessageMax brings better results, which can not only achieve efficient and rapid expression of various target proteins including nuclear proteins in various cell types, but also realize simultaneous transfection and expression of multiple factors.

Key words: Chemically synthetic modified message RNA, Liposome, Gene expression, Mouse embryonic fibroblast