Immunosensor-based rapid quantitative detection of Newcastle disease virus antibodies using innovative gold immunochromatographic assay.

Abstract

A novel quantitative method for rapid Newcastle disease virus (NDV) antibody detection was developed based on an innovative gold immunochromatographic assay with a quantitative immunosensor. NDV antibody-detecting test strips containing a two-reaction system and double-test lines (T1, T2) were prepared. The test results were judged according to the signal ratio between the test and control lines as measured by the quantitative immunosensor. The minimum detection limit of the test strips for NDV antibodies was 22 titres. In addition, the assay was highly specific because only NDV antibodies produced visible test lines on the strip. The clinical application of the strips was tested by detecting NDV antibodies in 506 serum samples collected from chickens. The results showed a coincidence of 92·49% with those of the haemagglutination inhibition assay. The strips were successfully prepared and showed high specificity towards NDV, sensitivity and stability. This study describes a new method for detection of NDV antibody and provides a reference basis for rapid and quantitative monitoring of NDV antibodies. This new method overcomes the limitation of the existing colloidal gold immunochromatography, which only produces qualitative or semi-quantitative results.