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Contents
Instructors
Useful Textbooks
Glaeser, Downing, DeRosier, Chiu, Frank: "Electron Crystallography of Biological Macromolecules"
Frank: "Three Dimensional Electron Microscopy of Macromolecular Assemblies"
Michael Moody, 1990, Biophysical Electron Microscopy: Basic Concepts and Modern Techniques, in Biophysical Electron Microscopy. ed. Hawkes & Valdre, Academic Press. p 145-287.
Steward: "Fourier Optics: An Introduction"
Reimer: "Transmission Electron Microscopy: Physics of Image Formation and Microanalysis"
Bozzola & Russell: "Electron Microscopy: Principles and Techniques for Biologists"
Harris: "Negative Staining and Cryoelectron Microscopy"
Williams & Carter: "Transmission Electron Microscopy: A Textbook for Materials Science"
Requirements
The following will be required for students desiring credit for this course:
Syllabus
Intro to EM, Optics, image formation and Diffraction - David Stokes (NYU)
- Basic EM techniques (TEM, SEM, STEM)
- Interaction of electrons with matter
- Image formation
- overview of 3D reconstruction strategies
- 2D crystallography
- helical reconstruction (Fourier-Bessel)
- single particle analysis
- tomography
- Physics of electrons
- Faraday's Law and Lorenz force
- Motion of an electron in a magnetic field
- electrostatic and magnetic lenses
- deflectors
- electron-specimen interactions
- particle-wave duality
- scattering cross-section
- elastic scattering
- inelastic scattering
- energy filter and zero-loss imaging
- EELS
- secondary electrons
- backscattered electrons
- x-rays
- microscope column
- condenser, objective, intermediate, projector lenses
- gun, beam, image deflector coils
- condensor, objective, selected area apertures
- optics
- focal length, magnification
- ray path diagram
- resolution
- aberrations
- coherence
- Radiation damage
- Electron diffraction
- Diffraction of waves - Frauenhofer vs. Fresnel
- Sum of cosines -> Fourier transform
Diffraction, Fourier transforms, CTF, cross-correlation - Bill Rice (NYSBC)
- Sum of cosines -> Fourier transform
- Example functions (Gaussian, box, delta fcn, cosine)
- Friedel's Law
- Convolution fcn
- Correlation fcn & Convolution Thm
- Projection Thm
- relative importance of amplitude and phase
- Nyquist limit
- Convolution and convolution theorem
- Correlation
- Effect of aperture in diffraction plane; point spread function
- image formation in the microscope
- weak phase approximation
- lens aberrations, defocus : CTF function
- Envelope functions
- Effect of CTF on images
- CTF correction
Tomography I - David Stokes (NYU)
- imaging considerations
- dose fractionation
- automated imaging and strategies for tracking
- equal tilt increments/cosine rule
- dual/single axis
- Alignment of images (fiducial vs. correlation)
- distortion correction (optical and mechanical)
- R-weighted backprojection vs. other reconstruction algorithms
- denoising (non-linear anisotropic diffusion vs. median filter)
- segmentation (automatic vs. manual)
- template matching and real-space averaging of subvolumes
- applications
Tomography II - David Stokes (NYU)
- Cryoelectron tomography
- Zero-loss imaging
- Resolution assessment
- Motif averaging
- Missing wedge compensation
Crystallography I - Iban Ubarretxena (Mt. Sinai)
Crystallography II - Iban Ubarretxena (Mt. Sinai)
- Braggs law
- real/reciprocal lattice
- unit cell
- symmetry
- Miller indices
- reciprocal lattice symmetry (ampl and phase)
- lattice lines
- convolution fcn -> crystal
- Projection Thm and radius of Ewald Sphere
- strategy for 3D recontruction
- imaging considerations
- electron diffraction
- spot-scan for images
- Unbending of 2D crystals
- electron diffraction for amplitudes
- imaging for phases
- merging data in 3D (lattice lines)
- temperature factor compensation
- resolution criteria (point-spread fcn)
Helical reconstruction - - Hernando Sosa (Einstein)
- Fourier transfor in cylindrical coord
- Bessel functions
- continuous helix
- discontinuous helix
- selection rule
- n,l plot
- layer lines
- G(n,l) -> g(n,l)
- geometrical corrections
- in-plane tilt
- out-of-plane tilt
- repeat distance
- averaging of G(n,l)
- weighting
- CTF correction
- filtering
- temp factor compensation
- resolution criteria
- symmetry groups
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< < | Practical Exercises in Tomography and Crystallography |
> > | Practical Exercises in Tomography and Crystallography Nov. 4-8
- Day 1: Processing individual images of 2D crystals
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> > | *2dx software package
- Day 2: Processing individual images of Helical Crystals
- Day 3 - Merging of data from Helical Crystals and 3D reconstruction
- Day 4 - Tomography 1
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- Generation of tomograms with eTomo
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- Joining of serial sections with eTomo
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- Day 3 - Processing individual images of 2D crystals
- Day 4 - Processing individual images of Helical Crystals
- Day 5 - Merging of data from Helical Crystals and 3D reconstruction * EMIP software package
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| | Single Particle Analysis I - Joachim Frank (Columbia University)
Single Particle Analysis II - Joachim Frank (Columbia University)
Single Particle Analysis III - Joachim Frank (Columbia University)
- alignment
- classification and class-averages
- how to get the initial model
- random conical tilt with defined orientations
- orientation determination using common lines
- 3D projection matching
- model bias
- refinement
- multivariable statistical analysis (MSA)
- defocus groups and CTF correction (Weiner filter)
- weighted backprojection, ART and direct Fourier reconstruction
- symmetry
- resolution criteria (Fourier Shell Correlation)
Practical Exercises in Tomography and Single Particle Analysis
- Day 1: single particle analysis 1
- Generation of initial model by Random Conical Tilt * use SPIDER
- Day 2: single particle analysis 2
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- 2d analysis / particle picking
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- Generation of initial model by Common Lines
- use both SPIDER and EMAN
- Day 3: single particle analysis 3
- Model generation and refinement using Projection Matching
- SPIDER
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- Day 4: Fitting of atomic coordinates into EM models
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| | Molecular fitting - Willy Wriggers (Weil Cornell Medical College)
- Boundary determination
- isodensity contour
- segmentation
- Automated strategies
- Criteria for fit
-- DavidStokes - 07 Aug 2013 |
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