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is an extended version of Sedfit for the global analysis of sedimentation velocity, sedimentation equilibrium, and/or dynamic light scattering experiments. At the same time, it is a stand-alone sedimentation equilibrium analysis software. Further, isotherms of weight-average sedimentation coefficients or weight-average molar mass values can be incorporated into the analysis, as well as isothermal titration calorimetry isotherms and surface binding isotherms. All data types can be mixed and simultaneously fitted, and Sedphat can be used as a general platform the global analysis of interacting systems in different experiments.
Sedphat was written at the National Institutes of Health and is freely distributed without charge for research use. The program can be downloaded from here but it is also available directly from sedfitsedphat.nibib.nih.gov. However, this website was written by the author in his private capacity, and no official support or endorsement of NIH is intended and should be inferred. disclaimer
The main purpose of this website is to provide information for using the software, such as an online help reference information, background information, and examples of what it does and how it can be used.
upcoming workshops:
March 4 - 8, 2013: Thermodynamic and Hydrodynamic Analysis of Marcomolecules in Solution - learning SEDFIT and SEDPHAT at the Laboratorio Nacional de Biociencias, Campinas, Brazil
contact Dra. Ana Carolina Migliorini Figueira, Spectroscopy and Calorimetry Lab, LNBio, Campinas, SP, Brazil (ana.figueira@lnbio.org.br)
May 20 - 24, 2013: Biophysical Methods for the Thermodynamic Analysis of Macromolecular Interactions at the National Institutes of Health, Bethesda, Maryland, U.S.A.
by the Foundation of Advanced Education in the Sciences, NIH; for registration visit http://events.r20.constantcontact.com/register/event?oeidk=a07e6w99ayu0b7aa7de&llr=k4uamblab
Please sign up to the SEDPHAT-L listserv for discussion of applications of SEDPHAT and questions of global analysis of ITC, AUC, and other biophysical techniques. This forum reaches currently ~ 160 colleagues in the field of studying macromolecular interactions with biophysical methodology.
NEW in version 8.2: fluorescence anisotropy, steady-state fluorescence, more ternary systems, multi-threaded interacting Lamm equation solutions, effective particle calculator
NEW in version 6.5: Partial boundary modeling, three-site binding models
NEW in version 6.1: Faster data analysis with multi-threading support and new Lamm equation solutions
NEW in version 4.3: simulated annealing optimization for complex error surfaces, several new utility functions, improved support of density contrast fitting, improved ITC support
NEW in version 4.1b: new ternary binding models, mass action law calculator, integration of distributions (like in SEDFIT), and several bug fixes.
NEW in version 4.0: isothermal titration calorimetry analysis, surface binding isotherm analysis, triple protein interactions, conformational change model, and various improved housekeeping operations, such as path-independent configurations, and several bug fixes.
NEW in version 3.0: Multi-signal sedimentation velocity for heterogeneous protein complexes
NEW in version 3.0: Isotherms for sedimentation velocity analysis using Gilbert-Jenkins theory,
NEW in version 2.0: Reaction kinetics for sedimentation velocity models of interacting systems
Main changes of version 1.9: save Sedphat configurations, save model parameters, and isotherm data type, among many other things.
The main features of Sedphat include:
 | sedimentation equilibrium: complete framework for global analysis of molar mass distributions, species analysis, self-associating proteins, and hetero-associations. Analysis features such as mass conservation constraints and multi-wavelength analysis are fully implemented. |
| sedimentation velocity: global analysis of multiple sedimentation velocity data (multi-signal capable), with continuous size-distributions, discrete species and hybrid models, as well as protein self-association models. |
| dynamic light scattering: discrete and continuous distributions |
| sedimentation isotherms: isotherms of weight-average s-values or Mw values can be analyzed with interacting systems models |
| isothermal titration calorimetry: delta-H isotherms from titrations of heterogeneous interactions |
| linear spectroscopy: for example, isotherms of fluorescence quenching, CD titrations |
| fluorescence anisotropy: anisotropy isotherms as function of solution composition |
| surface plasmon resonance: surface-binding equilibria as a function of analyte concentration (isotherms of steady-state signals), in direct binding or competition mode |
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global analysis: data sets from multiple experimental techniques can be combined in a global analysis. |
For AUC users, Sedphat will appear as a more powerful and flexible extension of Sedfit. Therefore, for the analysis of AUC data, I suggest for new users to get a little bit familiar with the basics of Sedfit, even if the main goal is sedimentation equilibrium analysis. The similarities with Sedfit include:
| same overall strategy of the sequence: loading data, selecting the model, fitting the model, saving the results |
| same conventions to load the data and graphically determine fitting limits, meniscus and bottom, zoom and unzoom |
| same display and copy options for saving results, data, and fits |
Because Sedphat extends the data analysis to global analysis of multiple experiments, possibly of different kinds, much more powerful models are possible. At the same time, however, the global analysis requires more complex structures for the data, the parameters, and their relationships. The present Sedphat help web concentrates more on these issues, rather than, for example, the detailed user-interface issues that are described in great detail in the Sedfit help system.
Compared to Sedfit, the main differences of Sedphat are:
| to facilitate global analysis of multiple experiments, the data can be save as 'experiments' (*.xp files) together with the local experimental and fitting parameters. |
| the parameters can be classified as global, shared local, or local parameters. |
| all parameters in Sedphat are corrected to standard conditions (water, 20C). This is in contrast to Sedfit, which is (almost) entirely in experimental parameters |
| concentration parameters and binding constants in Sedphat are in molar units, not signal units. |
You can find in this website
| an introduction to the concepts of Sedphat for getting started |
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For further inquiries send an email to pschuck@helix.nih.gov (or see the contact information).
search SEDFIT and SEDPHAT websites
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SEDFIT/SEDPHAT |
The information contained herein is provided as a service with the understanding that the author makes no warranties, either expressed or implied, concerning the accuracy, completeness, reliability, or suitability of the information.