Abstract
The assessment of biological product activity is a key aspect of quality control. Currently, in vitro assays serve as the primarily method employed by both companies and regulatory agencies to evaluate biological activity. Reporter Gene Assay (RGA) is a technique that investigates gene expression regulation and cellular signal transduction pathway activation through easily detectable reporter genes. RGA is highly dependent on drug mechanisms, offering high accuracy and precision, and has gained increasing recognition. The utilization of alternative analytical methods based on RGA have emerged as a prevailing trend, with a growing number of antibody drugs adopting corresponding RGA-based quality control approaches. Establishing stable expressing cell lines is essential to ensure the stability, reliability, and consistency of assays across diverse conditions when employing RGA techniques. CRISPR/Cas9 gene editing technology mediated site-specific gene integration allows for rapid and precise insertion of exogenous genes into specific genomic loci and enables the efficient construction of stable RGA cell lines, which would significantly propel the advancement of biological activity evaluation methods.