OKATEST - Detection of okadaic acid and derivatives in bivalve molluscs

Bivalves molluscs can very efficiently accumulate toxins from the algae that they eat and their consumption can infect the consumers. Among the different types of toxins found in shellfish, those producing diarrheic shellfish poisoning are very common and widely spread.

Okatest okadaic acid detection

Human consumption of shellfish contaminated with OA-toxins group (OA, DTX1, DTX2 and its esters) causes Diarrheic Shellfish Poisoning (DSP). Inhibition of serine/threonine protein phosphatases (PP1 & PP2A) activity by  this group of toxins is assumed to be responsible for these diarrheic disorders. OkaTest is a ready-to-use colorimetric phosphatase inhibition assay for quantification of OA-toxins. OkaTest is performed in a 96-well microtiter plate and is applicable to shellfish such as mussels, clams, oysters and scallops.

 Detection of  okadaic acid and derivates in bivalve molluscs
    • Fast: 43 samples in about 2 hoursokatest
    • Simple: two easy steps after extraction, ready-to-use OA standards
    • Quantitative: working range: 63 -352 µg/Kg
    • Suitable for:  bivalve molluscs
    • Kit presentation: 48 or 96 tests kits
    • Equipment: plate reader at 405 nm


  • Results from single laboratory validations, participation in proficiency tests and interlaboratory studies have shown that OkaTest complies with the legislation requirements for quantitative determination of OA-toxins in molluscs.
  • OkaTest can therefore be used as a supplementary test to the reference method for determination of the OA-toxins group in molluscs according to the Commission Regulations (EC) No. 853/2004 and No. 15/2011. http://aesan.msssi.gob.es/en/CRLMB/web/otros_procedimientos/other_crlmb_standard_operating_procedures.shtml


  • Smienk et al. 2012 Single Laboratory Validation of A Ready-to-Use Phosphatase Inhibition Assay for Detection of Okadaic Acid Toxins. Toxins, 5, 339-352.
  • Smienk et al. 2013. Quantitative Determination of the Okadaic Acid Toxins Group by a Colorimetric Phosphatase Inhibition Assay: Interlaboratory Study. Journal of AOAC International Vol. 96, No. 1.
  • Quasimeme laboratory performance studies 2012-2015

The colorimetric phosphatase inhibition assay, OkaTest, complies with the criteria stipulated by the European Reference Laboratory on Marine Toxins and Commission Regulation 15/2012 for determination of OA-group toxins in molluscs, according to the European Commission (DG-SANCO)

 Assay procedure

Okatest acid procedure