Automating Titer Measurement

A number of process analytic technologies (PAT) have been developed for optimizing cell attributes and culture media components, but increasing viable cell density (VCD) does not always produce a commensurate increase in product titer. Therefore, the measurement of antibody titers in CHO cell cultures is a critical process parameter (CPP) for optimizing cell culture conditions. Titer measurement must be rapid, robust, and the assay must have a wide dynamic range to monitor product yields throughout a bioreactor run.

This technical note describes how the HaLCon Protein Analyzer is capable of rapid, automated at-line measurement of antibody titers from stirred bioreactors using an aseptic sampling device. Learn how assay linearity and accuracy were evaluated over a measurement range of 0.1 to 6.5 g/L using a simulated cell culture titer curve spiked with bovine serum albumin (BSA) and human IgG. Manual and automated aseptic sampling measurements using the HaLCon analyzer compared very favorably with a commercial Protein A HPLC system. Excellent intra-assay precision (CV < 3%) was demonstrated for both off-line and at-line measurements.

Measurement results were also unaffected by BSA levels up to 2.5% (v/v).