Simplify CHO Cell Line Genetic Stability Testing With Whole Genome Sequencing

Stable transfection of expression vectors into Chinese Hamster Ovary (CHO) cells is utilized for establishing cell lines to produce recombinant protein products for therapeutic applications. Maintaining the genetic stability of the genes encoding the therapeutic protein is vital for consistent production. Any changes to these genes can compromise product integrity and patient safety, making it a regulatory requirement to prove that the expression construct remains stable without significant changes during cell culture and growth.

Genetic stability testing verifies that the correct coding sequence is stably integrated into the production cell line and remains consistent throughout the manufacturing process. While existing monitoring techniques used to assess genetic stability provide a broad view of the stability of the expression construct, they require a substantial number of cells, subjective interpretation of gels and karyotypes, and extensive pre-testing design work, including designing primers for multiple genes.

In contrast, whole genome sequencing (WGS) by Next-Generation Sequencing (NGS) offers a faster, sequence-agnostic approach for genetic stability testing that is not primer-directed or overly reliant on a large number of growing cells. Here, we describe the use of WGS to comprehensively assess genetic stability in clonally-derived CHO cell banks using the Aptegra™ CHO genetic stability assay.