Development and Characterization of the NISTCHO Reference Cell Line

Well-characterized reference materials enable successful collaborations within the scientific community by establishing common reagents for benchmarking studies and reducing the barriers to sharing materials and information. Here, we report the development of NISTCHO, a recombinant Chinese hamster ovary cell line expressing a nonoriginator version of the NISTmAb IgG1. We evaluated candidate clonal cell lines in a fed-batch cell culture model to assess growth and productivity of the cell lines and protein quality attributes of the recombinant IgG produced, which demonstrated suitability of multiple candidates. Selection of a preferred candidate was accomplished through sequencing-based analysis of the transgene integration sites, and a base-pair resolution map of the transgene integration site was developed and verified using PCR-based methods. Lastly, a validation study performed by an independent laboratory confirmed the robustness of the preferred candidate, which has been selected for further development as the NISTCHO reference cell line. Together, these results describe the origin of this new reference material and will serve as the foundation for future interlaboratory studies using the NISTCHO cell line.