The NISTmAb Reference Material (RM) 8671 is intended as a product-agnostic control to support biopharmaceutical innovation, and was therefore developed under a quality system of similar rigor to marketed biotechnology products. Quality of biotechnology products is defined as the suitability of the drug substance or drug product for its intended use . This term includes product quality attributes such as quantity, identity, biological activity, and purity. Appropriate specification setting to ensure quality for biotechnology products must be underpinned by rigorous characterization of physicochemical, biophysical, and immunochemical properties . The most immediate utility of the NISTmAb is for physicochemical/biophysical analysis technology development, method control, and harmonization of best practices. An expansive and continuously growing historical characterization dataset has been compiled as a foundation for these intended uses [3–8], a subset of which has been refined and qualified for quality monitoring [9–12], and used herein for quality attribute value assignment as part of the NISTmAb lifecycle management plan.