On Mon, Jul 07, 2008 at 11:15:57AM +0200, Thiemo Schreiber wrote: > Hello everyone, > > I have biological data from a competition experiment where a free ligand is > titrated against the binding of a protein. > > Now, I would like to fit a standard on-site binding curve to this data in > order to obtain the IC50 and Kd values. > Unfortunately I have not been able to find a package/function which allows > such a fitting and calculates the results. > > > Does anyone know if there is a suitable package available and which function > to apply? > > Thanks a lot. > > Cheers > Thiemo Schreiber > [[alternative HTML version deleted]]
this is probably what you are looking for: let x = vector of free ligand concenctrations y = vector of correspondng spec. protein bindings be defined in the R workspace. than use res <- nls( y ~ (x * Bmax) / (x + Kd), start = list(Bmax=, Kd=)) (providing some sensible start values for the free parameters , of course) cf. `nls' manpage for details ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
