The uncertainty in bioprocess operation motivates the need to study feasibility at the design stage, i.e., to find whether the operation under uncertainty is feasible and satisfies all required specifications. A new methodology to determine feasibility of bioprocesses and a quantitative feasibility measure, the feasibility index which represents the maximum process feasibility for a given design, have been developed in previous work.

This paper presents a case study of the application of the methodology and the feasibility index to a chromatographic process to purify antibody fragment from clarified lysate. While using centrifugation to clarify the lysate, a certain level of fine solids is expected to remain in the clarified lysate. One of the major issues in chromatography is fouling which is a long standing operating problem particularly at the manufacturing scale. One of the causes of fouling is the fine solid in the processing materials which is loaded to the column. This blocks the pores of column matrices. Such fouling leads to reduced the flow velocity in the column, decreased the process efficiency such as product yield and purity, and reduces the column life.

The case study on the chromatographic operation under uncertainty aims to find the feasible operating solution with the maximum process feasibility under the fouling. Furthermore, the feasibility index is used to compare the feasibility of bioprocess for different operating conditions. The case study also examines the long term influence of the fouling on the chromatographic operating. The results show solid fouling can significantly reduce the process feasibility in the long run. The feasibility index also indicates the quantitative interaction between the lysis clarification step and the chromatographic step.