DOTAP methylsulfat is a cationic lipid reagent derived from trimethylammonium, featuring two 18-carbon fatty acid tails each with a single alkene group. This compound can self-assemble with negatively charged ions (such as DNA) to form complexes that adhere to cell membranes and enter cells through electrostatic interactions and endocytosis. With its hydrophobic domains, DOTAP methylsulfat facilitates the fusion of endosomal membranes to release DNA into the cytoplasm, serving a role in gene delivery. It is widely used in research areas like gene therapy, cell transfection, and the design of non-viral vectors.