ELECTRON MICROSCOPY

Sample

NICOTINIC ACETYLCHOLINE RECEPTOR IN NATIVE POSTSYNAPTIC MEMBRANE FROM TORPEDO MARMORATA

Specimen Preperation
Sample Aggregation State HELICAL ARRAY
Vitrification Instrument HOMEMADE PLUNGER
Cryogen Name ETHANE
Sample Vitrification Details VITRIFICATION 1 -- CRYOGEN- ETHANE, HUMIDITY- 85 TEMPERATURE- 120 INSTRUMENT- HOMEMADE PLUNGER METHOD- BLOT UNTIL APPLIED DROPLET LOSES CONTACT WITH FILTER PAPER (INDICATED BY LOSS OF TRANSPARENCY TYPICALLY 6S) TIMERESOLVEDSTATE- VITRIFIED WITHIN 10MS OF EXPOSURE TO ACETYLCHOLINE (APPLIED AS THE GRID IS BEING PLUNGED USING A FINE FOCUSSED SPRAY POSITIONED ABOUT 1CM ABOVE THE ETHANE SURFACE) DETAILS- VITRIFICATION CARRIED OUT AT AN AMBIENT TEMPERATURE OF 8 DEGREES
3D Reconstruction
Reconstruction Method HELICAL
Number of Particles ?
Reported Resolution (Å) 6.2
Resolution Method ?
Other Details FOURIER-BESSEL SYNTHESIS AFTER APPLYING DISTORTION CORRECTIONS TO THE IMAGES. SUBMISSION BASED ON EXPERIMENTAL DATA FROM EMDB EMD-2071.
Refinement Type
Symmetry Type HELICAL
Map-Model Fitting and Refinement
ID 1
Refinement Space REAL
Refinement Protocol FLEXIBLE FIT
Refinement Target ?
Overall B Value ?
Fitting Procedure ?
Details METHOD--MAXIMISATION OF CORRELATION BETWEEN EXPERIMENTAL DENSITIES AND ATOMIC MODEL, USING A DEFORMABLE ELASTIC NETWORK ALGORITHM (DIREX) REFINEMENT PROTOCOL--LOW RESOLUTION X-RAY
Data Acquisition
Detector Type KODAK SO-163 FILM
Electron Dose (electrons/Å2) 25
Imaging Experiment
Date of Experiment 2005-11-01
Temprature (Kelvin)
Microscope Model JEOL 3000SFF
Minimum Defocus (nm) 900
Maximum Defocus (nm) 2000
Minimum Tilt Angle (degrees) ?
Maximum Tilt Angle (degrees) ?
Nominal CS 1.6
Imaging Mode BRIGHT FIELD
Specimen Holder Model .
Nominal Magnification 40000
Calibrated Magnification 38500
Source FIELD EMISSION GUN
Acceleration Voltage (kV) 300
Imaging Details STANDARD LOW DOSE IMAGING OF SPECIMENS OVER HOLES IN THE CARBON SUPPORT FILM
Imaging Experiment
Task Software Package Version
MODEL FITTING DireX ?
RECONSTRUCTION Custom ?
RECONSTRUCTION MRC IMAGE PROCESSING PACKAGE ?
Image Processing
CTF Correction Type CTF Correction Details Number of Particles Selected Particle Selection Details
? EACH TUBE IMAGE