This video showcases the cellular strucutre ofDesulfovibrio magneticusRS-1. This organism is highly divergent from AMB-1 and forms tooth-shaped crystals of magnetite. In our study of its biomineralization dynamics we found that it differed from AMB-1 in a number of interesting ways. Most importantly, it contained a second iron-containing organelle unrelated to magnetosomes and its magnetite crystals did not appear to be surrounded by a biological membrane. In this video, the results of an electron cryotomography study of RS-1 ultrasturcture are highlighted. For more information see: Byrne et al. PNAS 2010. Video by: Dr. David Ball and Professor Kenneth Downing.