Development of immunochromatographic test strips for rapid, quantitative detection of H9AIV antibodies.

To improve viral antibody detection and disease control, laboratories need faster and simpler methods for direct detection of H9AIV in clinical samples. In this study, test strips were developed for rapid detection of H9AIV antibodies in poultry serum by a sandwich method with double-line detection. The hemagglutinin protein was labeled with colloidal gold as a detection reagent and was blotted on the test lines, while goat anti-rabbit IgG was utilized on the control line of the nitrocellulose membrane. The test strips have high specificity, sensitivity, and stability, with a correlation coefficient of 0.9656 and coefficients of variation below 10%. Application of the kit to quantitative detection of H9AIV antibodies in 504 samples collected from chickens showed a coincidence rate of 80.56% with previously run HI assays.