The last public domain version of SVEDBERG is version 5.01 (January '97). The current version of SVEDBERG is not found here and is not freeware. It is distributed from John Philo's web site at http://www.jphilo.mailway.com as 'try before you buy' shareware.
These public domain versions of SVEDBERG are no longer supported, and lack the Help file and tutorials that come with the shareware version (versions 6.1 and later). These public domain versions also lack the features needed for fitting interference scans.
The program XLGRAPH which was formerly distributed along with SVEDBERG is now distributed separately, and should be available from all sites distributing the public domain version(s) of SVEDBERG.
John Philo's address and e-mail as shown in the public domain versions are no longer correct. He can be reached via e-mail at his 'permanent' e-mail forwarding address, jphilo@mailway.com
Please note that the program should always be described as SVEDBERG (in all capitals) to distinguish it from the person and unit.
PROGRAM DESCRIPTION (public domain version):
SVEDBERG simultaneously fits up to 40 scans to one of several different approximate solutions of the Lamm equation, to derive BOTH sedimentation and diffusion coefficients from the data. This means that you can also determine MW from a velocity experiment, and this can be accurate within a few percent for proteins of > ~5 kDa.
SVEDBERG is primarily intended for situations where diffusion makes the boundaries fairly broad. It can also fit up to 4 species, under the assumption that they are entirely non-interacting, and has functions for both conventional and synthetic-boundary cells. A rigorous error analysis to find confidence intervals for the fitted parameters can be performed. The data sets may have a baseline data set subtracted, and/or an overall zero offset may be included in the fit.
SVEDBERG is entirely menu and point-and-click driven. It can display high quality graphs of the data, overlaid data and fits, residual plots, etc., and all may be printed at publication quality or exported to word processors.
SVEDBERG will work with Windows 3.1 or Windows 95/98 running at VGA video resolution (640 x 480), BUT it is really designed to run at 800 x 600 video resolution or higher.
The fitting functions in SVEDBERG are computationally intensive, so the program wants a reasonably fast processor. For single species fits on < 10 scans a 486/33 processor would take a couple of minutes, but for multi-species fits on many scans you will want a 90 MHz Pentium or better.
Documentation is almost non-existent, but others who have used this program have found it to be reasonably intuitive.
You will want to read two articles describing this program and some examples of its usage. The first is Philo, J. (1994) "Measuring Sedimentation, Diffusion, and Molecular Weights of Small Molecules by Direct Fitting of Sedimentation Velocity Concentration Profiles" in "Modern Analytical Ultracentrifugation" (Schuster and Laue, eds., Birkhauser, Boston, pp. 156-170). This article describes the original version of the program (prior to version 5.00 in 1997) and should be available as an Adobe Acrobat .PDF document, including figures, as the file SVEDBERG.PDF, from wherever you obtained the program files.
The second article is Philo, J. (1997) "An Improved Function for Fitting Sedimentation Velocity Data for Low-Molecular-Weight Solutes", Biophysical J. 72:435-444. This article should also be available as an Adobe Acrobat .PDF file, SVEDDOC2.PDF, from the software distribution sites.
This article describes a new form of fitting function, the "modified Fujita-MacCosham function" which gives more accurate diffusion coefficients for low molecular weight species, and which accounts for restricted diffusion at the meniscus and can therefore be used for scans before the meniscus is cleared. This function was implemented as a program option beginning with version 5.01, and the function formerly used is still available but now called the "Fujita function". This article also describes further tests of fitting multiple species, fitting when the sedimentation coefficient is concentration-dependent, and discusses the effects of both random and systematic noise on the results. Reprints for this article are available upon request. (Please note that there was an inadvertent sign error in equations 1 and 2 in that article: the second term in the large brackets that begins with 2/sqr(pi) should be negative, not positive.)
The program is usually supplied via the Internet as a self-extracting,
self-installing archive SVEDyynn.EXE, where yynn are the year and sequence
number (to indicate the versions). Further information about installation
can be found in the file INSTALL.TXT that should be found at the same location.