DOTAP methylsulfate is a cationic lipid reagent and a trimethylammonium cation derivative, with two octadecanoic fatty acid chains in its molecular structure, each containing one unsaturated alkene bond. DOTAP can self-assemble with negatively charged nucleic acids such as DNA via electrostatic interactions to form complexes, which enter cells through electrostatic adsorption and endocytosis. The hydrophobic domain of DOTAP promotes endosomal membrane fusion and facilitates nucleic acid release into the cytoplasm, thereby achieving efficient gene delivery. Currently, DOTAP methylsulfate is widely used in gene therapy, in vitro cell transfection, non-viral vector construction, and related research fields.

DOTAP methylsulfate was mixed with DOPE at different mass ratios under experimental conditions of 4 h transfection + 24 h incubation. The transfection efficiency differed significantly among the ratios, with each ratio yielding a distinct optimal transfection outcome.In the Huh7 and AGS cell lines, the optimal ratios were T1P0 (mass ratio 1:0) and T3P1 (mass ratio 3:1). In A549 cells, the optimal ratios were T1P1 (mass ratio 1:1) and T3P1 (mass ratio 3:1). Studies indicated that the variation in optimal ratios was unrelated to the size and zeta potential of the liposomes themselves [1].
When DOTAP methylsulfate was mixed with lipids at specific ratios (e.g., 1:2, 1:1, 2:1), the DNA transfection efficiency mediated by the mixture was significantly higher than that of DOTAP methylsulfate alone. Moreover, the mixed system maintained stable transfection activity even at a serum concentration of 80%.In addition, experiments confirmed that the optimal mass ratio of DOTAP methylsulfate to DNA for efficient transfection was 12:1.DOTAP methylsulfate–DNA complexes formed in the presence of serum exhibited good stability against DNase I digestion after 30 min of DNase treatment, and cholesterol addition did not affect the structural integrity of the complexes.Flow cytometric analysis was performed 2 h after transfection using DOTAP methylsulfate labeled with 1% NBD-DOTAP methylsulfate. The results showed that cholesterol-modified liposomes bound significantly more to cells in the presence of serum than unmodified pure DOTAP methylsulfate liposomes [2].

Ethanol: 80 mg/mL (103.33 mM), Sonication is recommended.

DMSO: 4 mg/mL (5.17 mM)