Shaikh, T. R.; Gao, H.; Baxter, W.; Asturias, F. J.; Boisset, N.; Leith, A. & Frank, J. SPIDER image processing for single-particle reconstruction of biological macromolecules from electron micrographs Nature protocols, 2008, 3, 1941-1974
This protocol describes the reconstruction of biological molecules from the electron micrographs of single particles. Computation here is performed using the image-processing software SPIDER and can be managed using a graphical user interface, termed the SPIDER Reconstruction Engine. Two approaches are described to obtain an initial reconstruction: random-conical tilt and common lines. Once an existing model is available, reference-based alignment can be used, a procedure that can be iterated. Also described is supervised classification, a method to look for homogeneous subsets when multiple known conformations of the molecule may coexist.