The model describes a phospholipid bilayer that lies between two layers of globular proteins, which is both trilaminar and lipoprotinious.
[1] The phospholipid bilayer had already been proposed by Gorter and Grendel in 1925;[2] however, the flanking proteinaceous layers in the Davson–Danielli model were novel and intended to explain Danielli's observations on the surface tension of lipid bi-layers (It is now known that the phospholipid head groups are sufficient to explain the measured surface tension[3]).
Evidence for the model included electron microscopy, in which high-resolution micrographs showed three distinct layers within a cell membrane, with an inner white core and two flanking dark layers.
Despite the Davson–Danielli model being scientifically accepted, the model made assumptions, such as assuming that all membranes had the same structure, thickness and lipid-protein ratio, contradicting the observation that membranes could have specialized functions.
Furthermore, the Davson–Danielli model could not account for certain observed phenomena, notably the bulk movement of molecules through the plasma membrane through active transport.