Why is the IC not detectable although the analytical PCR is positive?
FAQ ID -1505

The IC serves to monitor both a potential PCR inhibition and the nucleic acid extraction efficiency (provided it was added to the extraction procedure). A positive IC in the absence of an analytical PCR signal confirms a true negative result. However, in the presence of a strong positive analytical PCR the IC may fail (or may be reduced in its fluorescence intensity level) as a consequence of competition of these two reactions for PCR resources in the artus® Master Mix.