Abstract

Characterization of critical reagents can mitigate adverse impact to ligand-binding assay performance. We investigated the conjugation conditions of a bispecific protein to SULFO-TAG NHS-Ester™ ruthenium to resolve a steady increase in ligand-binding assay background signal. Functional and biophysical attributes in stability samples revealed low pH (4.0) conjugation and formulation buffers were key to decrease aggregate formation. We also identified pH-specific (3.0) purification conditions to reduce aggregate levels from 37% to <5% of a mouse IgG3 reagent antibody. These case studies support the utility of biophysical and functional characterization of critical reagents as a proactive approach to maintain long-term stability and provide the basis for our recommendations a risk-based approach to establish re-evaluation intervals for traditional and novel reagents.

Keywords:

References

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Vol. 13, No. 10

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History

Received 21 August 2020

Accepted 26 February 2021

Published online 22 April 2021

Published in print May 2021

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Keywords

Acknowledgments

The authors acknowledge Glenn Miller, Qiang Qu, Mania Kavosi, Sheldon Leung, Kaitlyn Bushey and Denise O’Hara for experimental data.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

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Critical reagent characterization and re-evaluation to ensure long-term stability: two case studies

Abstract

References