qPCR: A Screening Tool For Harmful Algal Blooms

Oral Presentation

Prepared by M. Citriglia, N. Schafer
Northeast Ohio Regional Sewer District, 4747 East 49th Street, Cuyahoga Heights, OH, 44125, United States

Contact Information: CitrigliaM@neorsd.org; 216-641-6000


Lake Erie has seen an increase in the number of harmful algal blooms (HAB) caused by cyanobacteria (blue-green algae) as well as an increase in the severity of these blooms. The cyanobacteria present in the HABs can potentially produce toxins capable of causing illness and/or death. Timely and accurate identification and reporting of these toxins is critical for issuing water quality advisories. The analytical methods for toxin analysis are very expensive and selecting the correct analytical method can be difficult. Another challenge is the necessity for a skilled analyst available for microscopic algae identification. Furthermore, some cyanobacteria can produce multiple toxins. For example the genus Anabaena can produce anatoxin-a, saxitoxin, or microcystin and the genus Aphanizomenon can produce saxitoxin, anatoxin-a, or clylindrospermopsin. NEORSD decided to experiment with a rapid method utilizing Quantitative Polymerase Chain Reaction (qPCR) to screen for a total cyanobacteria gene and specific toxin producing genes (microcytins, saxitoxin, and cylindrospermopsin). The NEORSD laboratory experimented with the Phytoxigene, CyanoDTec qPCR assays as a means to screen samples submitted for cyanotoxin analysis. A portion of the sample submitted for analysis was filtered, and the DNA was extracted and analyzed on multiple qPCR platforms. The results of our study indicate that this method has the potential to eliminate the need for microscopic examination and assist with the selection of the appropriate method for toxin analysis.