Development of an expert system for selection and synthesis of protein purification processes

A ‘second generation’ of protein purification rules has been developed and implemented into a prototype expert system (ES) using a ‘shell’. The work has concentrated on developing a more precise and accurate knowledge base for selection of optimal large scale protein purification sequences. Expert knowledge was obtained partly from the literature but mainly from industrial experts working on the large scale separation of therapeutic, diagnostic and analytical proteins. The knowledge was expressed in ∼65 rules, some of which carry a degree of uncertainty. The downstream process was divided into two distinct subprocesses: a first subprocess called recovery after which the total protein concentration is 60–70 g l−1 and a second subprocess called purification. A limiting factor in the development of ESs for protein purification at present is the acquisition, clarification, formalization and structuring of the domain of expert knowledge. The main deficiency of accurate information was found to be in that required for the selection of high resolution purification operations on a rational basis. An expert system for selection of optimal protein separation sequences will give the user a number of alternatives chosen on the basis of extensive data back-up on proteins and unit operations. This constitutes a clear case of ‘expert amplification’ and not of ‘expert replacement’.