In order for proteins to adsorb, they must first come into contact with the surface through one or more of these major transport mechanisms: diffusion, thermal convection, bulk flow, or a combination thereof. When considering the transport of proteins, it is clear how concentration gradients, temperature, protein size and flow velocity will influence the arrival of proteins to a solid surface. Under conditions of low flow and minimal temperature gradients, the adsorption rate can be modeled after the diffusion rate equation.