Determination of parvovirus antigen in the vaccine using time-resolved fluorescence immunoassay.

As a highly contagious and potentially fatal disease of dogs, canine parvovirus type 2 (CPV-2) usually causes severe myocarditis and gastroenteritis, while vaccine injection has greatly reduced the incidence of CPV-2 diseases. However, there is currently a lack of simple and effective method for quantitative detection of CPV-2 in vaccine. Therefore, this study aims to prepare an accurate method to determine the CPV-2 antigen (CPV-2-Ag) in vaccine. Here a sandwich time-resolved fluorescence immunoassay (TRFIA) was established and optimized: Anti-CPV-2 antibodies were immobilized on 96-well plates to capture CPV-2-Ag, and then bound together with the detection antibodies labeled with Europium(III) (Eu3+ ) chelates; finally time resolved fluorometry was employed to measure the fluorescence intensity. Vaccination was performed to evaluate the relationship between CPV-2-Ag concentration and antibody titer. The sensitivity is 1.15 mEU/mL (LogY = 1.524 + 0.8667 × LogX, R2 = 0.9933)), and the average recovery is among 91.00% to 106.39% without cross reactions with the other canine viral antigen. The correlation between ELISA assay and this method is up to 0.9861. And, there is high correlation between the CPV-2-Ag concentration and antibody titers (R2 = 0.9234). This immunoassay established has high sensitivity, accuracy and specificity, which indicate that this method could be suitable for quantitative detection of CPV-2-Ag in vaccine evaluation. This article is protected by copyright. All rights reserved.