This kit applies the Competitive-ELISA as the method for the in vitro qualitative detection of concentration of antibodies to Avian Influenza Virus H7 (AIV-H7) in samples. The ELISA Microtiter plate provided in this kit has been pre-coated with the AIV-H7 antigen. In the experiment, add control serum, samples and Antibody Working Solution into plate.AIV-H7 antibodies in the samples will compete with the antibody in the working solution to bind with the antigen pre-coated on the Microplate. Then wash to remove unbound antibodies and other components, add the HRP Conjugate to specifically bind with the compound of antibody and antigen on the Microplate and the unbound HRP Conjugate will be removed by washing. Add TMB substrate to the wells, it will react with the enzyme and become blue, the shade of color is of negative correlation with AIV-H7 antibody levels in the samples. At last, end the reaction by adding Stop Solution to produce a yellow product. Measure the absorbance value of each well by using a Microplate Reader with 450 nm wavelength, then we can judge whether AIV-H7 antibody exist in the sample.