Hello,

I'm doing some IC50 curve fitting with the least-square curve-fit component. In general, it works fine except for sosme cases where the curve is not complete, for example the 100% inhibition point is experimentally lacking.

I tried to fix this by modifying the fitting parameters in a custom manipulator before the fitting component as follows :

#min := 0;
#max := 100;

InitialCoefficients := #min . ',' . #max . ',' . #initialLogIC50 . ',' . #initialSlope;

and asking the fitting component to leave the min and the max as they are by putting the following on coefficienttofitproperty:

CoefficientsToFitProperty : 0,0,1,1

Unfortunately, the calculated IC50 is wrong (-2.36 in place of -5 as 50% inhibition is reached at 10-5M - see below).

Fitted Log IC50 = -2.36 +/- 237

Can anyone help me finding the parameter that I should take into account to correctly calculate this kind of dose-response curves ?

Thanks.