Okadaic Acid is an aquatic toxin that may be accumulated in the fatty tissues of shellfish and other fish. It is produced by microalgae, particularly troublesome during algal blooms, and also leads to contamination of the water itself. This compound is stable even when heated to high temperatures, so boiling or cooking contaminated water or food sources will not destroy the toxin. Consumption of these materials poses a risk to human health causing a variety of severe health problems.
Because there is no easy treatment for contaminated materials, many countries have set strict regulations for acceptable levels of this toxin in seafood. However, the traditional testing methods require highly complex labor-intensive and time-consuming sample preparation. In order to efficiently screen a large number of samples, a new method is necessary.
A New Testing Method
Therefore, a new polarization fluorescence immunoassay (FPIA) has been developed. This FPIA method uses a portable analyzer, requires only minimal sample preparation, and each test requires only 5-10 minutes to complete. First, a fluorescent tracer molecule selectively binds with okadaic acid. Then, this conjugate molecule interacts with specific anti-okadaic acid monoclonal antibodies. Several reference samples with known concentrations are analyzed, and then the actual sample is analyzed and compared.
The Traditional Testing Methods
Previous methods relied on either ELISA (enzyme-linked immunosorbent assay), requiring several hours and tedious sample preparation, or ICA (immunochromatographic analysis), requiring 10-40 minutes and more limited level of detection. In addition, these methods require the sample testing to be performed in a laboratory, which is less convenient.
Both climate change and pollution are leading to more frequent algal blooms in recent decades. Therefore, the ability to monitor for these toxins is becoming increasingly important.
Hendrickson O, Mukhametova L, Zvereva E, et al. A sensitive fluorescence polarization immunoassay for the rapid detection of okadaic acid in environmental waters. Biosensors (Basel). 2023 Apr 16;13(4):477. doi: 10.3390/bios13040477. PMID: 37185552