Detection of Ochratoxin A Using An Automated Chemiluminescent Immunoassay Based on Acridinium Ester-magnetic Microspheres
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
An automated chemiluminescent immunoassay (CLIA) based on acridinium ester-magnetic microspheres was established for the detection of ochratoxin A (OTA) in milk. Anti-mouse IgG antibodies were conjugated to magnetic microspheres and the OTA-BSA conjugates were labeled with acridinium ester. Different CLIA experimental conditions, including magnetic microsphere concentration, OTA antibody concentration, labeled OTA-BSA conjugate concentration, OTA antibody and labeled OTA-BSA dilution, reaction time, and sample pre-treatment conditions, were optimized. Under the established optimal conditions, the following results were obtained using the CLIA method: a limit of detection of 6.38 ng/kg, a half-maximal inhibitory concentration (IC50) of 31.40 ng/kg, a linear range of 11.23 to 99.20 ng/kg, and intra- and inter-assay coefficients of variation <8%. When determining OTA in milk samples, the limit of detection was 25.52 ng/kg, the IC50 was 125.60 ng/kg, the linear range was 44.92 to 396.80 ng/kg, and the addition recovery was 95.08% to 105.83%. The cross-reactivities with ochratoxin B and ochratoxin C were 6.52% and 24.57%, respectively, and there was no obvious cross-reaction with other mycotoxins. Milk sample detection values obtained using the CLIA method were consistent with those obtained using high-performance liquid chromatography-tandem mass spectrometry. Moreover, the reagents used for the CLIA method could be stored stably for more than 9 months at 2~8 ℃. In conclusion, the CLIA method established in this study is sensitive, accurate, rapid, and easy to operate. The detection time is only 30 min, and the method is particularly suitable for the rapid screening of OTA residues in large-scale milk samples.
