The Presto CT/NG kit is the only kit that can detect duplicate infections. The Presto CT/NG kit uses an Isolation and Amplification control [IAC]. IAC is a check that is added before the isolation is done, its function is that the IAC monitors and controls the efficiency of the isolation. In the event of an isolation error, no IAC is present in any of the samples. The IAC is added by a certain amount that it becomes negative when the detection of CT or NG is linked to a high positive sample, meaning that there is competition between the strong CT and NG signal and the IAC amplification. If CT and/or NG is high positive then IAC is negative and selectors are used to boost IAC.