Sensitive and Quantitative Detection of Severe Acute Respiratory Syndrome Coronavirus Infection by Real-Time Nested Polymerase Chain Reaction

Jiang, Shih Sheng; Chen, Tsan-Chi; Yang, Jyh-Yuan; Hsiung, Chao A.; Su, Ih-Jen; Liu, Ying-Lan; Chen, Po-Cheng; Juang, Jyh-Lyh

A quantitative, real-time, nested polymerase chain reaction (PCR) method, combining the high sensitivity of nested PCR with time-saving real-time instrumentation, was developed for large-scale screening for severe acute coronavirus (SARS) coronavirus. Forty-six clinical specimens were analyzed by this method, and results were compared with those obtained by conventional, single-round, real-time reverse-transcriptase PCR (RT-PCR) performed in parallel. Of the 17 positive results, 2 identified by our method were not detected by single-round, real-time RT-PCR, which suggests that real-time nested PCR has the potential for increased sensitivity, leading to earlier detection of SARS.