Rapid Detection of toxic Alexandrium by Loop-Mediated Isothermal Amplification Method

Loop-mediated isothermal amplification method (LAMP) is a novel nucleic acid amplification technology. The LAMP method amplifies DNA with rapidity, high specificity and sensitivity under isothermal conditions. This thesis took toxic Alexandrium as the major research object. DNA template was extracted by boiling method and specific primer was designed for LAMP assays. Toxic Alexandrium were quickly detected by LAMP technology. LAMP and PCR were successfully compared in the sensitivity of detecting Alexandrium minutum. Without gel electrophoresis, the LAMP amplification was directly visualized in the reaction tube by addition of SYBR Green I for a naked-eye inspection. The result indicated that toxic Alexandrium was detected by LAMP technology within 1 h under isothermal condition at 65 ℃. The lower detection limit of the LAMP reaction was 200 cell/ml, while that of the PCR was 1000 cell/ml. The LAMP assay is more simple, rapid and sensitive than the PCR. Furthermore, as LAMP technology does not require sophisticated instrumentation, it is very suitable for diagnosis in the fields.