How methylene blue goes through the cell surface membrane?

Methylene blue can pass through the cell surface membrane primarily through passive diffusion, especially in its uncharged form. At physiological pH, methylene blue exists mainly as a cation due to its positive charge, which can limit its ability to readily diffuse across the lipid bilayer. However, it can also enter cells through specific transport mechanisms, such as active transport or endocytosis, where it is taken up by cells via membrane invagination. Once inside the cell, methylene blue can exert its effects, often as an electron acceptor in various biochemical processes.