[soupastupid]

Log    dA/min
   0.6386
-2   0
-3   0.149
-4   0.5454
-5   0.5692
-6   0.6125

hey guys
This is my data.  My prof told me to use sigmaplot to analyze the data.  I plotted the data on a the xy scatter but could not find how to calculate IC50.

Could someone help me?
Step by step instructions.
I've searched for a tutorial on sigmaplot but to no avail.

I know IC50 is the inhibition at 50% concentration but sigmaplot is not user friendly
thanks guys
-andrew

[aliu]

Hi,

I first need to make a disclaimer that I am a Hitachi Software representative.

I have done your curve fit using MasterPlex ReaderFit which is dose response analysis software with automatic IC50 calculations (and much more).  I have fit your data using the 4 parameter logistic (4PL) nonlinear regression model equation and here it is =)



The C parameter in the 4PL represents your IC50 value which, in your case, is .00025 (or 2.5 * 10^(-4)).

I excluded your 0.6386 data point because there is no Log value associated with it.  

Here is a blog post that covers how you can calculate IC50 values or even something like IC90 with MasterPlex ReaderFit.

I hope this helps.  Please let me know if you have any questions.

Allen Liu