In-Culture Antibody Capture Using Transient CHO Expression Systems

Antibody therapeutics have demonstrated transformative impacts on improving the quality of life of millions of patients, whereas advances in antibody discovery technologies have imposed a significant production challenge for the generation of a large diversity of therapeutic antibody candidates. A demand for the rapid production of dozens of purified antibodies in 10-mg quantities is entailed for functional screening and molecular assessment studies. Here, we present a robust semi-automated production protocol that bridges the gap between miniaturized high-throughput screenings and conventional custom-scale workflows. This methodology and workflow utilize a simple high-titer transient Chinese hamster ovary (CHO) cell host-CHO4Tx^® expression system, a procedure of magnetic protein-A bead in-culture antibody capturing, and a semi-automated purification process with the GenScript AmMag^TM SA Plus system. This production protocol has been proven to be robust and valuable for the routine production of dozens of antibody constructs per week in sufficient quality and quantity for cell-based and biophysical studies. Key features • This protocol utilizes the high-titer CHO4Tx^® cell line, which helps increase protein production throughput by decreasing culture volume and eliminating DNA/transfection reagent complexation. • This protocol simplifies and expedites protein production processes by eliminating time-consuming and costly steps such as cell centrifugation, medium filtration, and medium column loading. • Although we present this workflow using CHO4Tx^®, magnetic bead purification methods can be applied to other CHO cell lines and human embryonic kidney-293 cells.