Use of end-point real-time pcr for patient follow-up

[alvaro.guerrero]

Dear all,

I am a newcomer to the world of real-time PCR. Currently, I am working on the virus PCR section at a big hospital in London. We are using Taqman probes for most of our assays, which we run on 2 7500 fast instruments (applied Biosystems). For some viruses, such as respiratory viruses, we perform end-point analysis to provide a yes-no answer. The hospital has many immunocompromised in-patients that require serial monitoring in order to verify whether they have cleared the infection. My question is as follows, Is the increase in Ct values obtained on sequential samples from a patient indicative of decreasing viral load, and thus can be used to inform the clinician that the infection is clearing, or the Ct values obtained from a patient at different timepoints of their infection are not comparable when performing qualitative real-time pcr and thus only a negative-positive s interpretable.

Sorry for this long question and thank you very much

Alvi