Scientific journal
Scientific Review. Biological science
ISSN 2500-3399
ПИ №ФС77-57454

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DEVELOPMENT OF METHOD FOR THE OCHRATOXIN A DETECTION BY BIACORE OPTICAL BIOSENSOR

Safenkova I.V. 1 Kostenko S.N. 1 Petrakova A.V. 1 Urusov A.E. 1 Sadykhov E.G. 1 Zherdev A.V. 1 Dzantiev B.B. 1
1 A.N. Bach Institute of Biochemistry Russian Acad. Sci. (119071
Two schemes of competitive immunoassay of ochratoxin A (OTA) with the use of optical biosensor Biacore system were developed and tested. In the first sheme antibodies are immobilized, and the competition of free OTA and OTA conjugate is carried out in solution. In the second scheme OTA-protein conjugate is immobilized, and free OTA and immobilized OTA compete for binding sites of antibodies. For the reaction of monoclonal antibodies and OTA, immobilized on the surface of the biosensor’s chip, average values of the constants wee determined. The kinetic association constant is equal to 3.5*104 М-1 s-1, kinetic dissociation constant is 2.4*10-4 s-1 and equilibrium dissociation constant is 1.5*108 М-1. Competitive assay with lower limit of detection was realized for the scheme with immobilized conjugate. Limit of OTA detection is 0.4 ng/mL, working range of OTA quantitative determination is 0.520 ng/mL, and the standard deviation (n=3) does not exceed 7%. Maximal standard deviation of the signal was obtained in the range of high (> 10 ng/mL) concentrations. The duration of one measurements cycle is 12 min.