Endonuclease (Serratia marcescens) is a critical ancillary material used to degrade host cell nucleic acids and remove residual DNA during biopharmaceutical and cell & gene therapy manufacturing. As regulatory expectations for ancillary material qualification continue to rise, the demand for standardized, activity-based analytical methods has become increasingly important. To support assay consistency in Endonuclease material qualification programs, USP has proposed General Chapter <89.3>, featuring a validated enzymatic activity method and a highly characterized qualitative Reference Standard (Endonuclease S. marcescens, Catalog No. 1235470), evaluated through collaborative studies conducted by USP and collaborating laboratories. Eurofins BioPharma Product Testing has implemented this standardized method and validated that the method demonstrates fitness-for-purpose and supports phase-appropriate control strategies. The method delivers consistent, reproducible results suitable for lot release and comparability assessments.

In this presentation, we will discuss:

• The role of Endonuclease in biopharmaceutical and cell/gene therapy manufacturing.
• Regulatory drivers for ancillary material qualification and phase-appropriate control strategies.
• Details of USP General Chapter <89.3> and its significance in standardizing endonuclease activity testing.
• How the validated spectrophotometric assay quantifies endonuclease activity via DNA substrate degradation with absorbance at 260 nm, enabling calculation of enzymatic activity and specific activity.

Presenters:

	John Brabazon Raw Materials Group Leader Eurofins BioPharma Product Testing
John Brabazon leads the biologics raw materials method establishment services at Eurofins BioPharma Product Testing. He brings six years of experience in analytical method development and validation, with expertise in establishing assays for non-compendial raw materials. His work includes the development of functional assays for ancillary materials used in cell and gene therapy manufacturing.
	Ben Clarke Principal Scientist USP
Ben Clarke develops USP physical reference standards for biologics and ensures their consistent quality and suitability for use. It is his pleasure to work with laboratories across the world to rigorously test USP reference standards and develop new compendial methods. He is the scientific lead for USP’s cell and gene therapy expert volunteers, who are partners in developing standards and quality solutions for advanced therapies. Before joining USP, Ben developed potency bioassays for mRNA and RSV vaccines at GSK. His post-doctoral research at the NIH included developing mouse models using CRISPR/Cas9 genome editing. He received his Ph.D. in Cell Biology from Cornell University and his B.S. in Biochemistry from the Pennsylvania State University.

Moderator:

Erica Cates Regional Sales Manager Eurofins BioPharma Product Testing

Erica Cates is a Regional Sales Manager for Eurofins BioPharma Product Testing, and is based at the Lancaster, PA facility. She serves as a strategic partner to clients across the Maryland and Washington, D.C. region, helping them navigate the Eurofins network and ensuring streamlined access to comprehensive testing solutions and project support. She earned her bachelor’s degree in biochemistry from Providence College.