Sensitive time-resolved fluoroimmunoassay for the quantitative detection of okadaic acid

Abstract

Okadaic acid (OA) is a biotoxin from marine microalgae and widely present in shellfish, which severely affects the seafood safety. Therefore, it is essential to establish a highly sensitive OA analysis and detection method. In this study, a new type of immunoassay technology was established on the basis of the competition method using time-resolved fluoroimmunoassay (TRFIA). OA-bovine serum albumin (OA-BSA) coated on a 96-well plate competes with OA standard or samples to bind OA antibodies. A rare-earth ion-labeled secondary antibody, which fluoresces strongly under the effect of the enhancement solution, was then added as a tracer for detection. The established linear range of OA detected by TRFIA was 2.49 × 10-3 – 50 ng/ml, and the limit of detection was 2.49 × 10-3 ng/ml. The average coefficients of variation from intra-assay and inter-assay batches were 3.34% and 5.87%, respectively, and the recovery rate was 93.04%–111.66%. The OA in shellfish samples was determined by TRFIA and high-performance liquid chromatography (HPLC), and the results showed a good correlation. This study established a TRFIA to detect OA, which has the characteristics of simplicity, sensitivity, precision, and high accuracy, far exceeding the EU or the US standards for the detection of shellfish toxins. It is expected to make proper contribution in marine biotoxin detection.

Okadaic Acid Detection through a Rapid and Sensitive Amplified Luminescent Proximity Homogeneous Assay

“…Moreover, AlphaLISA is a homogeneous assay in which the components involved in the immune response are dispersed in the solution, increasing the efficiency of the reaction and thereby reducing the time. The detection range and detection sensitivity of our previously established assay OA-TRFIA were optimized by nearly five-fold compared with ELISA (detection limit 12 pg/mL, detection range 20–750 pg/mL) [ 24 , 36 ]. The OA-AlphaLISA established in this study reduced the detection time to one-fourth based on the application of the no-wash strategy while maintaining the same detection range and sensitivity compared with the TRFIA.…”

Apigenin suppresses the low oxaliplatin-induced epithelial-mesenchymal transition in oral squamous cell carcinoma cells via LINC00857

“…The process of converting epithelial cells into mesenchymal cells is referred to as epithelial-mesenchymal transition (EMT) ( 11 , 12 ). The phenotypic changes in tumor cells during epithelial tumor metastasis are primarily induced by environmental stimuli, enabling them to adapt to various encountered microenvironments such as intercellular matrices, components of body fluids, or blood ( 13 - 15 ). For oral squamous carcinoma cells (OSCCs), EMT plays an essential role in their local recurrence and lymph node metastasis, affecting patient survival by regulating EMT associated factors ( 16 ).…”