ELISA analysis and Excel - Convert OD into concentration using Excel (Jun/04/2009 )
This page has everything you need to do a 4PL without needing to download, install or configure any software:
Just paste in your raw data. There's also an Add-in for Excel available at http://www.myassays.com/introducing-excel-add-in.html if you need to do it from Excel.
Hitachi Software has just launched a free online version of our desktop ELISA analysis software with 4PL & 5PL curve fitting models and much more: http://www.ReaderFit.com
Just like MasterPlex ReaderFit, the core curve fitting algorithms are 8+ years in the making and also includes weighting algorithms which are a necessity when dealing with heteroscedastic immunoassay data.
Here is a sample of the results you can get plus there will be MUCH more on the way as far as statistics go. Stay tuned! =)
Hitachi Solutions America, Ltd.
If you're doing a linear regression for your standards you can use the Excel template mentioned in this answer to automatically calculate the formula for the standard and use it to quantify your OD values. The link has some instructions on how to use it, but it's pretty self explanatory.