Statistical analysis of measurement errors of binding data in the Farr technique

A detailed statistical analysis of measurement errors in the Farr technique is performed, and approximated formulas for the error covariances are given. These formulas are then checked by means of experimental data. In particular, the analysis shows that the usually adopted linear extrapolation for the estimate of total antibody sites concentration may lead to relevant errors in the affinity distribution determination due to the low accuracy of data at high values of free hapten concentration. Conversely, this analysis may constitute the basis for implementing an optimal estimate procedure.