REAL-TIME ISOFORM ANALYSIS BY 2-DIMENSIONAL CHROMATOGRAPHY OF A MONOCLONAL-ANTIBODY DURING BIOREACTOR FERMENTATIONS

A humanized monoclonal antibody specific for L-selectin exhibits two d istinct isoforms that are distinguishable by a charged group modificat ion on one of the antibody light chains. The added charge allows basel ine separation of the isoforms by anion-exchange chromatography. Since this modification most likely results from specific enzymatic activit y within the Golgi complex, it is possible that fermentation condition s may affect the relative amounts of the isoforms produced. Herein is described a two-dimensional chromatographic method for quantifying the relative amounts of the isoforms from fermentation broths, in real ti me. (C) 1998 Elsevier Science B.V. All rights reserved.