Application of a micromembrane chromatography module to the examination of protein adsorption equilibrium

A micromembrane chromatography module based on a 96-well plate design and enabling fast and simple separation of small amounts of proteins was used for the determination of binding capacities of lysozyme, bovine serum albumin, ovalbumin, bovine γ-globulin, and human immunoglobulin G on a hydrophobic membrane Sartobind® Phenyl. Dependence of the binding capacity of the proteins on the ammonium sulfate concentration was examined in the salt concentration range of 0.5-2.0 mol L(-1). An exponential increase of the binding capacity was observed for all proteins. Simple Langmuir one-component isotherm was found suitable for the characterization of the effect of protein concentration in all cases. A combined effect of protein and salt concentrations was expressed via the Langmuir exponential isotherm and fitted the adsorption data for three of the investigated proteins well.