Manual


Global Nonlinear Least-Squares Equilibrium Analysis:

Quickstart Information:

  1. Step: Either load one or more equilibrium data sets with "Load Data" or load an existing fit with "Load Fit"

  2. Step: Change the project name to a sensible name (different from equilibrium data, and no spaces!)

  3. Step: Select a model by clicking on "Select Model"

  4. Step: Edit noise of each scan by scrolling through all scans and dragging the mouse over noisy data ranges. Datapoints highlighted in red will be discarded. Reset original scan limits by clicking on "Reset Scan Limits"

  5. Step: Run "Scan Diagnostics", review excluded scans (marked in blue) and override by double-clicking on the entry in the listbox.

  6. Step: Initialize parameters by clicking on "Initialize Parameters". Review molecular weight settings, override suggested values if necessary. If molecular weight is changed, re-run "Initialize Parameters", and select "Current Molecular Weight".

  7. Step: Load or create wavelength profile, or enter extinction coefficients manually (in OD/mol*cm), also enter buffer density and vbar values.

  8. Step: Set floatable parameters to be fitted by clicking on "Float Parameters". Change if needed in "Model Control" dialogue.

  9. Step: Run "Check Scans for Fit" for a final check before fitting. If successful, the "Fitting Control" button will be activated, and can now be selected. Otherwise, review error messages and fix.

  10. Step: Select "Fitting Control". Review settings in fitting control and select "Fit".

  11. Step: After converging, save fit and attempt a fit using the "Autoconverge" fitting mode. When saving, a default name is provided, which should not be changed to assure all related files can be found during project report generation. Repeat fitting until no further improvement is observed. If program "hangs", "Abort" fit and check amplitudes of all scans. Values should be negative or close to zero. Also check to see if the log of the association constant is reasonable (monomer-dimer: 8-12, trimer 18-26, tetramer: 25-35, all in molar units).

  12. Step:Close model control and select different model. Re-initialize and repeat fitting from step 6.

Detailed Description of Global Nonlinear Least-Squares Equilibrium Analysis


www contact: Borries Demeler

This document is part of the UltraScan Software Documentation distribution.
Copyright © notice.

The latest version of this document can always be found at:

    http://www.ultrascan.uthscsa.edu

Last modified on July 4, 2005.