The Bacillus megaterium expression system allows efficient protein expression without any proteolytic degradation (akaline proteases are lacking in B. megaterium. Moreover, no endotoxins are found in the cell wall. A versatile polylinker enables easy cloning and production of N-terminal authentic proteins. The xylose operon ensures a very tight regulation: target genes (even those encoding potentially toxic proteins) cloned in the provided vectors are overexpressed (up to 350-fold) only after xylose induction. The system is thus suited for cost-effective industrial large-scale protein production, particularly as inexpensive substrates are used for culturing. Target proteins can be expressed with either a 6×His or a Strep tag or both, enabling purification via affinity chromatography and specific detection by commercially available antibodies. In addition, the kit allows for intracellular as well as extracellular expression of target proteins in high yields; proteins can optionally be secreted into the culture medium. B. megaterium protoplasts ready for transformation are also available. MoBiTec GmbH 49 551 707 220 www.mobitec.com