Beckman Coulter, Inc.
 

Resource Center

 
 
 
 
 
 
 
   
   
 
 

A Suite of Sedimentation Equilibrium/Velocity and Utilities Software

Printer Friendly

Authored by: Dr. Les Holladay

Available at:

Multifit (Sedimentation Equilibrium Software) -- Windows* 95/NT

  1. Mixedfit. This is for the simultaneous analysis of one to 12 Optima™ XL-A/XL-I analytical ultracentrifuge sedimentation equilibrium absorbance or interference datafiles. The user can select either a single ideal species, single non-ideal species, ideal self-association, non-ideal self-association model, one of four ideal isodesmic models, an ideal or non-ideal dimer-hexamer isodesmic-hexamer model, or an ideal or nonideal monomer-dimer-hexamer isodesmic-hexamer model. The baseline absorbances can be floated in the curvefitting. The user needs to know the extinction coefficient of the species at the wavelengths used and the fringe factor for interference flies so that one may globally fit data at different wavelengths, rotor speeds, optical systems, and loading concentrations.
  2. Eqdata. This program will generate test data files for Optima XL-A data analysis software. The type of system, data, noise, etc. may all be specified. Graphs of Mw, Mz, etc. may be generated and printed.
  3. Polyfit. This program implements Lechner's method for estimating the molecular weight distribution of a polymer from sedimentation equilibrium data from three to seven different initial loading concentrations. See Lechner's manuscript in "Modern Analytical Ultracentrifugation" for details.
  4. DelGElec. This program estimates the electrostatic repulsion free energy in kJ/mol for two touching uniformly charges spherical monomers using the Overbeek Verwey model. A short table is sent to a memo pad, and the monomer molecular weight, the vbar, the temperature, and the bounds for ionic strength and net charge may be specified.
  5. Polydata. Computes synthetic datafiles for testing Polyfit.

EQFIT (Sedimentation Velocity and Utility Software) - Windows 3.x

  1. DENFIT. Reads in an AVIV file of absorbance (or ellipticity) versus temperature. Estimates Td, DH at Td, (and optionally DCp) from the data using a nonlinear regression fit with the Simplex algorithm. The user may allow either the pretransition value to be sloping, the post-transition value, or both.
  2. DSCFIT. Reads in a DSC file (a sample is included) Estimates Td, DH at Td, (and optionally DCp) from the data using a nonlinear regression fit with the Simplex algorithm. The user has many choices of models.
  3. GdmFit. This program works much like DenFit, except that it is for fitting guandinium chloride unfolding data. The data is essentially any observable vs. molar guandinium chloride concentration. The user has a choice of three extrapolation models. For any model the baselines are floated in the curve fit if desired. Sample datasets are *.gdm files.
  4. UreaFit. This program works much like GdmFit, except that it is for fitting urea unfolding data. The data is essentially any observable vs. molar urea concentration. The user has a choice of three extrapolation models. For any model the baselines are floated in the curve fit if desired. Sample datasets are *.ure files.
  5. NazMz. this program takes an interference sedimentation equilibrium datafile and applies Nazarian's method to estimate the apparent Z-average molecular weight across the solution column. This is useful for heterogeneous systems, but not for single species systems based on trial data.

(Sedimentation Velocity and Utility Software) - MS-DOS*

  1. A0CALC. Using an estimate for the buoyant molecular weight as found by MIXEDFIT, this program computes the unredistributed absorbance at 0 rpm. Useful for stability studies to track loss of protein with time.
  2. ABSFILES and INTFILES. Lists either Optima XL-A absorbance files with header info in a specified directory or Optima XL-I fringe files in a specified directory.
  3. PLNSEDEQ. An interactive screen to help plan sedimentation equilibrium runs. The program asks for the rotor speed, temperature, partial specific volume, molecular weight, and asymmetry and estimates the concentration gradient and the time required to reach equilibrium.
  4. SPEEDEQ. This program is an aid to reducing time to sedimentation equilibrium by overspeeding. One enters molecular parameters and the two times and speeds. The program estimates the lack of departure from the true equilibrium pattern.
  5. PLOTAPEQ. Given molecular and cell parameters this program plots out curves for approach-to-sedimentation equilibrium and the final equilibrium distribution. A useful simulation tool for planning experiments.
  6. AXIAL. A program to take hydrodynamic data and plot a cross-section of the equivalent prolate ellipsoid. Useful simulation and analysis tool.
  7. XLADATA. A program to manipulate Optima XL-A datafiles outside the user interface.
  8. PLOTVEL. A program to plot sedimentation velocity profiles given s, D, rotor speed, and the radial distance to the meniscus. A useful simulation and planning program.

* All trademarks are the property of their respective owners. Where applicable, the PCR process is covered by patents owned by Roche Molecular Systems, Inc., and F. Hoffmann-LaRoche, Ltd.

 
 
Home | Products | Customer Support | Resource Center
Employment | Our Company | Contact Us | Site Map
 Privacy©1998 - 2009 Beckman Coulter, Inc.