The five-parameter logistic: a characterization and comparison with the four-parameter logistic.

@article{Gottschalk2005TheFL,
  title={The five-parameter logistic: a characterization and comparison with the four-parameter logistic.},
  author={Paul G. Gottschalk and John R. Dunn},
  journal={Analytical biochemistry},
  year={2005},
  volume={343 1},
  pages={54-65}
}
Improvements in assay technology have reduced the amount of random variation in measured responses to the point where even slight asymmetry of the assay data can be more significant than random variation. Use of the five-parameter logistic (5PL) function to fit dose-response data easily accommodates such asymmetry. The 5PL can dramatically improve the accuracy of asymmetric assays over the use of symmetric models such as the four-parameter logistic (4PL) function. Until recently, however, the… CONTINUE READING