Calibrator Material Selection: A Key Criteria During Biomarker Assay Method Development

Abstract

Biomarker assay method development is a multistep rigorous process and calibrant material selection is integral to ensuring the quality of such assays. However, the impact of selection of calibrator material may often get overlooked. In this article, we highlight three case studies where biomarker calibrant material selection was deemed an essential criterion for consideration. Through these case studies we highlight challenges faced, steps taken and discuss the impact on assay-related decision-making. We also provide additional perspectives for selection and characterization of calibrant proteins in the setting of an evolving biomarker context of use.

Overcoming Lot-to-Lot Variability in Protein Activity Using Epitope-Specific Calibration-Free Concentration Analysis

“…To the author’s knowledge, this is the first study to describe a method to standardize CFCA measurements and demonstrate the subsequent utility of CFCA in overcoming lot-to-lot reagent variability across multiple assay platforms. Many methods have been applied to reagent generation and characterization to ensure a certain degree of quality and consistency. − But lot-to-lot variability in potency often remains, perhaps due to minor deviations in protocols and/or the natural heterogeneity of the expression systems used to produce protein reagents. While controlling expression, purification, and storage conditions are and will continue to be critical to ensure reagent quality, CFCA provides a complementary means to focus the definition of a protein concentration on only the species that can produce a response in the assay-of-interest.…”