title: Automatic acquisition of fiducial markers and alignment of images in tilt series for electron tomography.
abstract: Three-dimensional reconstruction of a section of biological tissue by electron tomography requires precise alignment of a series of two-dimensional images of the section made at numerous successive tilt angles. Gold beads on or in the section serve as fiducial markers. A scheme is described that automatically detects the position of these markers and indexes them from image to image. The resulting set of position vectors are arranged in a matrix representation of the tilt geometry and, by inversion, alignment information is obtained. The scheme is convenient, requires little operator time and provides an accuracy of < 2 pixels RMS. A tilt series of 60-70 images can be aligned in approximately 30 min on any modern desktop computer.
authors.affiliation: Department of Neurobiology, Stanford University School of Medicine, CA 94305, USA.
authors.forename: D
authors.initials: D
authors.lastname: Ress
authors.forename: M L
authors.initials: ML
authors.lastname: Harlow
authors.forename: M
authors.initials: M
authors.lastname: Schwarz
authors.forename: R M
authors.initials: RM
authors.lastname: Marshall
authors.forename: U J
authors.initials: UJ
authors.lastname: McMahan
mesh_terms: D000465:Algorithms; D000818:Animals; D006046:Gold; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron / Q000379:methods*; D008863:Microspheres; D018482:Muscle, Skeletal / Q000648:ultrastructure; D009469:Neuromuscular Junction / Q000648:ultrastructure*; D011894:Rana pipiens; D014054:Tomography
chemical_list: D006046:Gold