Try GraphPad Prism, it is designed for binding analysis.
A demo is available on:
http://www.graphpad.com
or
ftp.graphpad.com
I consult for them so this is for information only (no sales pitch).
_________________________________________________________
Rick Neubig RNeubig at umich.edu
University of Michigan Phone (313) 763-3650
http://www.umich.edu/~rneubig FAX (313) 763-4450
