Description

Using the supplied IC50 template, some data sets produce an IC50 value that, while numerically correct, is a negative rather than a positive value. This is due to the way that the IC50 equation is defined by the program, which treats negative and positive IC50 values the same in order to avoid calculation errors arising from taking logarithms of negative numbers.

Versions affected

Version 4 up to and including 4.0.18; version 5 up to and including 5.0.6. Later revisions incorporate these fixes and are not affected.

Work-around

Revised IC50 template and IC50 equation definitions can be downloaded from the links below. The template file should be copied to your

\Program Files\GraFit x\Templates

directory. The equation definitions should be copied to your

\Program Files\GraFit x\Components\IC 50

directory. Please consult your system administrator if you are unsure about locating these directories on your system.