Abstract: This invention is directed to characterizing a host system suitable for the production of functional transgenic proteins, such as anti-human IgG, for use in applications requiring Government regulatory approval. It is well known that regulatory agencies required stable, consistent master cell banks and master cell lines for the production of transgenic proteins in order to ensure sufficient material for appropriate characterization, clinical trials, and potential sales. Current plant production systems require the establishment of seed banks for this purpose. However, there are many draw backs related to such a system for the production of a continuous reliable transgenic protein source. An aspect of this invention is directed to characterizing a plant production system suitable for transgenic proteins that meet the stringent regulatory requirements.