The NISTmAb material is a recombinant humanized IgG1κ expressed in murine suspension culture. It is an »150 kDa homodimer of two identical light chains and two identical heavy chains linked through both inter- and intra-chain disulfide bonds. The protein has low abundance post-translational modifications including methionine oxidation, deamidation, and glycation. The molecule also has N-terminal pyroglutamination, C-terminal lysine clipping, and glycosylation of the heavy chains. These and other product quality attributes were extensively characterized in the ACS book series "State of the Art and Emerging Technologies for Therapeutic Monoclonal Antibody Characterization" for the initial batch of material (interim material 8670), used as the Primary Standard (PS) herein. Multiple bulk substance containers were homogenized to form a second batch (14HB batch) of material that was aliquoted into 1 L containers. A single 1 L container of 14HB was diluted 10-fold and aliquoted as RM 8671 lot 14HB-D-001.
A vial of RM 8671 contains 800 µL of 10 mg/mL IgG1κ monoclonal antibody in 12.5 mmol/L L-histidine, 12.5 mmol/L L-histidine HCl (pH 6.0). The material was produced in murine suspension cell culture and has undergone industry standard upstream and downstream purification to remove process related impurities.