# A Robust, High-Titer, Semi-Automated, and In-Culture Antibody-Capturing Transient CHO Platform Technology

## TL;DR

This paper introduces a new semi-automated system for efficiently producing large quantities of purified antibodies using a high-yield CHO platform and streamlined purification methods.

## Contribution

A novel semi-automated antibody production workflow combining a high-titer transient CHO system and magnetic ProA bead purification is introduced.

## Key findings

- The CHO4Tx® system achieved antibody yields of 200 mg/L or higher across diverse antibody constructs.
- The magnetic ProA bead process reduced production time by eliminating centrifugation and filtration steps.
- The system can produce ~20 mg of crude antibody per 100 mL flask with throughput for 19 constructs in a single run.

## Abstract

Background: Recent advances in antibody discovery technologies, especially progress in de novo synthesis through machine learning, have imposed a significant production challenge for the generation of a large diversity of antibodies against nearly any target of interest. There is a demand for the rapid production of dozens of purified antibodies in 10-milligram quantities sufficient for functional screening and molecular assessment studies. Objectives: To meet this requirement, a semi-automated production methodology and workflow was developed to bridge the miniaturized high-throughput screenings (HTSs) and the conventional custom-scale workflow by taking advantage of four new technology applications. Methods: First, it exploited a novel, simple, high-titer transient expression system, “CHO4Tx®”, which could achieve high yields in the range of 200 mg/L and above, across a variety of antibody constructs, including challenging targets. The consistently high yields from this transient CHO platform enabled the delivery of ~20 mg of crude material per 100 mL scale flask production with a throughput capacity of nineteen constructs in a single run. Secondly, we established a magnetic ProA bead in-culture antibody-capturing process, which significantly shortened the production timeline by eliminating the steps of cell centrifugation, filtration, and medium column loading. Third, we utilized the GenScript AmMag™ SA Plus semi-automation, which could handle magnetic ProA bead elution for 12 constructs within less than 1 h. Lastly, we transformed the AKTA PureTM system into an automated buffer exchange purification system with a capacity of processing 19 samples in a single run. Results and Conclusions: This new production platform was proven to be robust and could be applied for the routine production of antibodies of sufficient quality and quantity in support of cell-based assays and biophysical characterization.