This kit was based on sandwich enzyme-linked immune-sorbent assay technology. Anti- HD3 antibody was pre-coated onto 96-well plates. And the biotin conjugated anti-HD3 antibody was used as detection antibodies. The standards, test samples and biotin conjugated detection antibody were added to the wells subsequently, and wash with wash buffer. HRP-Streptavidin was added and unbound conjugates were washed away with wash buffer. TMB substrates were used to visualize HRP enzymatic reaction. TMB was