Marine dinoflagellate Alexandrium minutum producing paralytic shellfish toxins is responsible for paralytic shellfish poisoning (PSP). To investigate its temporal distributions in Chinhae Bay where PSP occurs annually, SYBR GreenⅠ based A. minutum-specific real-time PCR probe was developed on the LSU rDNA region. Assay specificity and sensitivity were tested against related species, and its specificity was further confirmed by sequencing of field-derived samples. Ten months field survey in 2008 (a total 100 surface water samples) by using the real-time PCR probe showed that A. minutum was detected at very low densities of 1-4 cells L-1 in May and June being spring in Chinhae Bay, Korea.

Abstract
 1. Introduction1
 2. Materials and Methods
  2.1. Cultures
  2.2. Collection of surface water samples fromChinhae Bay
  2.3. DNA extraction
  2.4. Design of a SYBR GreenⅠ-based real-timePCR probe specific for A. minutum
  2.5. Assay specificity of theA. minutum-selectivereal-time PCR probe
  2.6. Verification of assay specificity by sequencingof environmental samples
  2.7. Real-time PCR conditions
  2.8. Standard PCR conditions
  2.9. Standard curves for enumeration of cell numbers
  2.10. PCR inhibitor removal/template DNA dilutionfrom surface waters
 3. Results
  3.1. Specificity ofA. minutum-selective real-timePCR assay
  3.2. Standard curve and detection limit
  3.3. Temporal changes inA. minutum abundancesin Chinhae Bay
 4. Discussion
  4.1. Quantitative detection ofA. minutum in naturalenvironments
  4.2. Temporal distributions of A. minutum
 5. Conclusion
 References

• Tae-Gyu Park(Ecology and Oceanography Division, National Fisheries Research and Development institute (NFRDI)) Corresponding Author
• Yang-Soon Kang(Ecology and Oceanography Division, National Fisheries Research and Development institute (NFRDI))