Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V.

We describe a design of experiments approach that can be used to determine and model the influence of transgene regulatory elements, plant growth and development parameters, and incubation conditions on the transient expression of monoclonal antibodies and reporter proteins in plants.

Tobacco plants were used to produce a fungal cellulase, TrCel5A, via a transient expression system. The expression could be monitored using a fluorescent fusion protein, and the protein activity was characterized post-expression.

The design-of-experiments procedure presented here allows the evaluation of different flocculants in terms of their ability to aggregate dispersed particles in plant extracts, thus reducing turbidity and the costs of downstream processing.

Three heat precipitation methods are presented that effectively remove more than 90% of host cell proteins (HCPs) from tobacco extracts prior to any other purification step. The plant HCPs irreversibly aggregate at temperatures above 60 °C.

A method was developed to determine the specific heat capacity and thermal conductivity of leaf tissue by non-invasive, contact-free near infrared laser probing, which requires less than 1 min per sample.

In this procedure, a DsRed-based epitope ligand is immobilized to produce a highly selective affinity resin for the capture of monoclonal antibodies from crude plant extracts or cell culture supernatants, as an alternative to Protein A.