Automated platform buffer screening for multiple proteins on Big Kahuna

Importance of the Topic

Screening formulation buffers is essential in biotherapeutic development to ensure protein stability. Buffer composition, pH, ionic strength and additives directly influence conformational, chemical and colloidal stability. Automating this process accelerates formulation optimization, reduces manual workload and improves experimental consistency.

Study Aims and Overview

This application note describes the use of Big Kahuna to perform a platform buffer screen on four monoclonal antibodies in twelve buffer formulations. The goal was to demonstrate high-throughput automated buffer exchange, targeting >96% exchange and maintaining protein concentration at 10 mg/mL.

Methodology

Four mAbs were prepared at 10 mg/mL and exchanged into buffers composed of 10 mM histidine at pH 6.0 or 6.2, each containing one of five excipients or no excipient. Each condition was run in duplicate on a 96-well Unfilter plate. The buffer exchange protocol targeted 96% total exchange per pool, with 67% volume removal per cycle. Big Kahuna adjusted pressurization time in real time based on acoustic volume sensor feedback.

Applied Instrumentation

• Big Kahuna automated buffer exchange platform with pressure chamber and on-deck liquid handling
• Unfilter 96 and Unfilter 24 ultrafiltration plates
• Acoustic volume sensor for precise volume measurement
• Lunatic spectrophotometer using A280 application for protein concentration
• LEA software suite for experimental design and analysis

Key Results and Discussion

• Exchange Efficiency: Average exchange per pool was 98.4%, ranging from 96.7% to >99.9%, exceeding the 96% target.
• Mass Recovery: Protein mass recovery was consistently high (97–100%), indicating minimal loss during exchange.
• Concentration Consistency: Final concentrations averaged 10.0 mg/mL, matching initial levels with only minor variation.
• Throughput and Timing: All 48 exchanges completed in approximately 5 hours, with average cycle time of 9.3 minutes across seven cycles.

Benefits and Practical Applications

Automated buffer exchange on Big Kahuna enables rapid screening of multiple proteins and formulations with minimal hands-on time. Real-time adjustment of pressurization cycles ensures consistent exchange without over-concentration. High mass recovery and concentration fidelity support reliable downstream analytical workflows.

Future Trends and Opportunities

Integration of in-line concentration measurement and automated buffer preparation could further streamline the workflow. Virtual or physical coupling of spectrophotometric analysis with Big Kahuna would eliminate manual concentration checks. Expansion to larger Unfilter formats could scale throughput for industrial applications.

Conclusion

Big Kahuna provides an efficient, reproducible platform for high-throughput buffer screening of biotherapeutics. Automated ultrafiltration/diafiltration achieves target exchange levels and concentration control, supporting accelerated formulation development.

References

Unchained Labs. Automated platform buffer screening for multiple proteins on Big Kahuna Application Note. 2019 Rev C.