Fitting and handling dose response data.

The half maximal response of any compound in a biological system is a fundamental measure of the compound's potency whether the activity of the compound is beneficial or detrimental. As such, the estimation of this response as an Ec50 or an Ic50 results in a value that has fundamental significance in the determination of the potential of a compound. A collection of these values provide an invaluable data framework for understanding structure-activity relationships and computational method development and benchmarking. Therefore, understanding the errors and reproducibility issues associated with Ic50 determinations is essential for their robust calculation. This paper will discuss the practical approaches to the use of the Levenberg-Marquardt minimization method to fit dose response data and evaluate the resultant data in a statistically rigorous way.