Buffer exchange using size exclusion chromatography, countercurrent dialysis, and tangential flow filtration: Models,...

Area of Science:

• Biotechnology
• Chemical Engineering
• Protein Chemistry

Background:

• Industrial-scale protein purification relies on efficient buffer exchange methods.
• Key technologies include size exclusion chromatography (SEC), tangential flow filtration (TFF), and countercurrent dialysis (CCD).
• Optimizing these processes requires a comparative analysis of their technological and economic performance.

Purpose of the Study:

• To compare SEC, TFF, and CCD for industrial protein buffer exchange.
• To develop new mathematical models for direct comparison of unit operations.
• To identify the optimal technology based on process variables and economic factors.

Main Methods:

• Development of new mathematical models for comparing SEC, TFF, and CCD.
• Introduction of the 'diavolume equivalent' concept for SEC.
• Evaluation of variables: buffer exchange range, dilution, yield, buffer needs, operating time, throughput, plant space, capital, raw materials, and labor costs.

Main Results:

• TFF and CCD demonstrate a broader range of buffer exchange compared to SEC.
• TFF allows for simultaneous protein concentration.
• TFF and CCD offer a 2- to 5-fold improvement in efficiency for key variables (time, buffer, space) compared to SEC for equal batch sizes and yields.
• TFF and CCD lead to reduced manufacturing plant size and better utilization of facilities.

Conclusions:

• TFF and CCD are generally more advantageous than SEC for industrial buffer exchange due to efficiency and cost-effectiveness.
• SEC or CCD may be preferred if protein denaturation is a concern with TFF.
• The choice of technology depends on specific process requirements, scale, and protein characteristics.