Measurement of product titer is pivotal in bioprocess development. A typical monoclonal antibody production process involves multiple unit operations from upstream to final product release. We have developed a target-agnostic assay to measure the concentration of IgG or Fc-fusions during the discovery, cell culture development, and in-process phases of the biopharmaceutical process train. An antibody in complex, UV-absorbing culture fluid cannot readily be detected, limiting the ability to take quick process decisions, and reducing productivity. Our fluorescence-based monitoring technology overcomes some of the current barriers by allowing homogeneous and near-instantaneous (&lt; 30 seconds) IgG-measurements. We demonstrate application of this technology for batch and continuous IgG detection. In our approach, IgG-containing cell culture fluid is mixed with fluorescein-labeled Fc-binding ligands to produce a shift in fluorescence polarization, which can be detected in a batch or continuous-flow format. While screening various Fc-binding ligands for monitoring of human IgG we also identified ligands which signal the presence of IgG by changes in fluorescence intensity, which is readily detectable with inexpensive hardware. We observe significant shifts in both polarization and intensity in CHO cell culture fluid spiked with human IgG and can detect 0.005-0.1 g/L human IgG in protein A column breakthrough at a flow velocity of 80 cm/hr. We have successfully evaluated IgG-monitoring at a flow rate of 900 ml/hr without significant delay in fluorescence intensity signal. The fluorescence intensity information was applied to automatically switch columns when IgG-breakthrough of 0.005 g/L was reached. This technology provides a fast and reliable way to detect IgG in a flowing stream (or culture or batch samples) without elaborate sample preparation. Similar approaches can be envisioned for the detection of host cell proteins, DNA, and non-mAb products.

Monitoring of antibody throughout bioprocessing by fluorescence reporter with applications for protein A column process control

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.