Leginon: a system for fully automated acquisition of 1000 electron micrographs a day. by Potter, C, Chu, H, Frey, B, Green, C, Kisseberth, N, Madden, T, Miller, K, Nahrstedt, K, Pulokas, J, Reilein, A, Tcheng, D, Weber, D, Carragher, B