Adsorption Isotherms and Irreversible Binding of Proteins on Commercially Available Hydrophobic Adsorbents

Quantitative data about the behavior of proteins in different downstream processing unit operations are needed. Adsorption isotherms that are usually used to design such process steps may not be sufficient as for protein binding there is to distinguish between an adsorbing and a desorbing branch of the isotherm, leading to different apparent adsorption coefcients for adsorption and desorption, respectively. It is demonstrated that two different proteins show simultaneously reversible as well as irreversible ”adsorption” in hydrophobic interaction protein chromatography and that the reversible and the irreversible part of the apparent ”adsorption” isotherm can be separated.