1. RNA extraction 的過程要有 positive and negative controls
2. PCR 的過程要有要有 positive and negative controls **並且加上一個inhibition control (the patient sample spiked with a weak positive control to detect PCR inhibitory substances)
3. duplicate 要從 sample preparation, RNA extraction做起,不可以只在PCR部分做duplicate
如果有以下三種duplicate,可以提高PCR診斷的specificity and reliability