Simple and rapid antigen detection of server acute respiratory syndrome coronavirus

[[abstract]]A global outbreak of a new emerging disease, severe acute respiratory syndrome (SARS), was associated with a novel coronavirus, SARS-CoV. Transmission within hospitals was a major contributor to disease amplification. Thus, confirmation on SARS-CoV infection is important for managing patient care and for preventing nosocomial transmission. Currently, diagnosis of the infection in the early phase mainly relies on molecular method like RT-PCR and Real-time RT-PCR, while serological testing was reliable as a retrospective diagnostic method in convalescent phase. Although the molecular diagnosis methods provide a powerful tool in laboratory testing, the practical application in the point-of-care site is impeded by its complex protocols and sophisticated equipments. In this regard, a more simple and rapid diagnosis method is urgently needed. We have generated a series of polyclonal and monoclonal antibodies to the nucleocapsid (N) protein and successfully developed a rapid detection kit for SARS-CoV. By using the principle of immunocromatographic test, the antigen of SARS-CoV from nasopharyngeal aspirate or throat swab can be detected within 20 minutes on the dipstick strip. The test strip contains gold-conjugated antibodies as detection signal. These antibody-gold conjugates specifically react with N protein from sample and lateral flow on the nitrocellulose membrane that is coated with high affinity antibody. The red color of antibody-antigen-antibody sandwich is gradually deposited on the nitrocellulose membrane and this signal can be easily judge by naked eyes. The whole test procedure is less