PURIFICATION OF IgM and IgA

This chapter considers different strategies for the large-scale purification of immunoglobulin M (IgM) and immunoglobulin A (IgA). The choice of strategy depends on the biological environment of the target antibody and its intended use, and this also determines whether a single-step or multistep process is required. Each immunoglobulin has its own characteristics that could prevent interactions with the chosen chromatography medium. At the process scale, the choice is more restricted due to costs, leachables, validation requirements, and supplier constraints. Therefore, simpler technologies such as ion exchange remain advantageous for very-large-scale processes. Radial chromatography uses a short bed height with a large surface at the inlet and a small surface at the outlet, avoiding aggregation on the surface of the gel and concentrating the sample for elution. Monolith or membrane technologies could be used instead, but different chemistries must be used at each step to increase the selectivity of the overall process.