Author Archives: Pete Gagnon

How to Choose an Industrial Cation Exchanger for IgG Purification

    Cation-exchange chromatography is the third most used industrial method for antibody purification after anion-exchange and protein A affinity chromatography. It is most commonly used as an intermediate step but continues to attract attention as a capture method. This offers obvious cost and cleaning advantages over protein A but also imposes some sacrifices, all of which are discussed in a number of recent articles (1,2,3,4,5). Whichever application may be intended, end users seek a common set of performance characteristics.…

Minibodies and Multimodal Chromatography Methods

    Small, genetically engineered immunological constructs are being developed industry-wide for a growing range of in vivo applications. Examples include Fab, F(ab’)2, single-chain (sc) Fv, bis-scFV, diabodies, minibodies, and single-domain antibodies (1). Their small size potentially gives them access to tissues that are poorly accessible by intact antibodies; rapid clearance from blood and nontargeted tissues; lower immunogenic response; and eye-drop, inhalant, or oral administration. We report here on purification of an affinity-matured, humanized, antiprostate stem-cell antigen (PSCA) minibody for…

The Emerging Generation of Chromatography Tools for Virus Purification

Chromatography media and methods have evolved continuously since their introduction a half century ago. Traditional methods use columns packed with porous particles. They still dominate chromatography applications in the field of virus purification, but the past 20 years have witnessed the ascendance of alternative supports, namely membranes and monoliths. These newer media exploit the familiar surface chemistries — ion exchange, hydrophobic interaction, and affinity — but they use unique architectures that offer compelling performance features. The Architecture of Chromatography Media…