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Immunocaptured PCR (ic-PCR) technique, combining the enrichment character of immunocaptured method to infectious microbe and specific amplification feature of PCR technique, is one of the most ideal specific and quick diagnostic methods. In this study, ic-PCR was used to detect the following four severe infectious microbes: Vibrio cholerae, Escherichia coli O157, SARS-Cov and AIV.1. All the three immunocaptured methods: microwell, microtube and IMS (Immunomagnetic sphere), can specifically capture the Vibrio cholerae, Escherichia coli O157, SARS and AIV, respectively, from environmental samples or human samples. Comparing to the traditional separating culture methods, these methods will save much time. Especially for IMS, due to its high capability and better reaction dynamics, should be the optimal immunocaptured method for these four microbes.2. Bacteria detection: Multi-PCR with our designed specific primers from rfb gene and ctx gene of O1 and O139 Vibrio Cholerae, can detect and identify O1 and O139 Vibrio cholerae, and even differentiate the epidemic or non-epidemic strains of El Tor O1, effectively. The obtained partial rfb gene and ctx gene sequences are completely identical to the sequences of El Tor O1 (str. N16961) and O139 Vibrio cholerae under accession No.AE004113 and No.Y07786, respectively. The detection threshold is less than 100cfu/ml. For E.coli O157, nest-PCR generated 497 bp fragment according to Nathalie’s primers, and the obtained sequence is complete identical to E.coli O157: H7 under accession No.S83460. The detection threshold is about 10~2 cfu/ml by microtube method, which is less than that by IMS method.3. SARS-Cov detection: Real time PCR combined microwell method can avoid false positive results which were observed in Real Time PCR with whole RNA templates extracted from samples directly. The detection threshold is about 101 copies. The sensitivity is 10хhigh as that of commended Real Time PCR diagnostic kit for SARS-Cov.
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