Guinier parameters

Interactive and automated data processing tools (PRIMUS, GNOM, AUTORG).
Scattering from simple bodies (BODIES), peak analysis (PEAK), data plotting (SASPLOT) etc.
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Guinier parameters

#1 Post by oavina24 » 2018.08.02 08:50

Could someone link me to a detailed explanation of all these parameters, what they do and how they are suppose to be. I'm fairly new to saxs and would like to learn how to use this software.
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PRIMUS Guinier wizard parameters

#2 Post by AL » 2018.08.03 12:44

  • I0: Forward scattering I(0).
  • Rg: Radius of gyration - the average of square center-of-mass distances in the molecule (weighted by the scattering length density). It is a measure for the overall size of a macromolecule.
    If the experimental data are in inverse angstroms (Å-1), Rg is provided in angstroms (Å).
    If the experimental data are in inverse nanometres (nm-1), Rg is provided in nanometres (nm).
  • sRg limits:
    the first value is smin*Rg where smin is the s (or q) value of the first point of the chosen Guinier interval;
    the second value is smax*Rg where smax is the s value of the last point of the chosen Guinier interval.
    sRg values should be less than 1.0; however in most cases it is acceptable if smax*Rg < 1.3.
  • Fidelity: a legacy estimate of how linear the Guinier approximation is, please ignore.
  • Particle type:
    globular - provides Rg as defined above;
    rod - provides Rg of the cross-section for very long particles.
  • Range: first and last point of the interval used for I(0) and Rg Guinier approximation.
Check out the EMBO practical course on solution scattering from biological macromolecules 19 - 26 November 2018 | Hamburg, Germany

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