Gram-negative bacterial cells possess two membranes - the inner cytoplasmic membrane and the outer membrane. The two membranes are distinct in their composition; the inner membrane is composed of a phospholipid bilayer. whereas the outer membrane (OM) is composed of an asymmetrical bilayer. with the outer leaflet containing lipopolysaccharide (LPS) (Raetz and Whitfield. https://allfixelectricales.shop/product-category/seal-kit-bowl-mount/