title: A new general method for designing affinity chromatography processes.
abstract: Affinity chromatography is widely used for selectively recovering a target solute from a complex mixture. The challenge in designing a capture process is to achieve high yield, high column utilization, and high sorbent productivity while satisfying loading time and pressure limit requirements. The conventional design method based on constant-pattern waves cannot be used for small feed batches or short columns, which do not allow the formation of such waves. Other design methods in the literature rely on simulations or experimental trials, and can be time-consuming and costly. In this study, a new design method with no need of simulations is developed for constant pattern and non-constant pattern systems with Langmuir isotherms. Given feed conditions, loading time, and desired yield, the design requires only the values of certain intrinsic parameters, which can be estimated from a small number of bench-scale experiments. The minimum column volume for capture can be estimated either graphically or analytically. The method is tested with Protein A chromatography data for antibody purification. It is applicable to a wide range of production scales and design requirements. The effects of material properties, feed composition, feed volume, and design requirements on the column volume for capture can be found graphically. When the loading time relative to a characteristic diffusion time is 0.5 or larger, the minimum column volume approaches that of an ideal system. A short loading time increases sorbent productivity, but increases the minimum column volume. A high feed concentration, a high equilibrium capacity, and a small diffusion time relative to the loading time can reduce the minimum column volume and increase productivity.
authors.affiliation: School of Chemical Engineering, 480 Stadium Mall Drive, Purdue University, West Lafayette, IN 47907-2100, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Ling
authors.affiliation: School of Chemical Engineering, 480 Stadium Mall Drive, Purdue University, West Lafayette, IN 47907-2100, USA.
authors.forename: Lee-Wei
authors.initials: LW
authors.lastname: Kao
authors.affiliation: School of Chemical Engineering, 480 Stadium Mall Drive, Purdue University, West Lafayette, IN 47907-2100, USA. Electronic address: wangn@ecn.purdue.edu.
authors.forename: Nien-Hwa Linda
authors.initials: NH
authors.lastname: Wang
mesh_terms: D002846:Chromatography, Affinity / Q000379:methods*; D004058:Diffusion; D057230:Limit of Detection; D013205:Staphylococcal Protein A / Q000378:metabolism; D013997:Time Factors
chemical_list: D013205:Staphylococcal Protein A
keywords: Affinity chromatography; Capture process design; Langmuir isotherm; Maximum productivity; Minimum column volume; Protein A chromatography