ELISA
Standard wells and blank wells were set in accordance with the protocol
of the Bioswamp ELISA kit. Serum (40 μl) was added to each sample well,
and 10 μl biotinylated antibody and 50 μl HRP-conjugated reagent were
added to each well except the blank well. After incubating for 30 min at
37°C, washing buffer was added to every well and samples were rested for
30 s five times. Then, chromogen solution was added to each well and
samples were incubated for 10 min at 37°C. Lastly, stop solution was
added to terminate the reaction and the optical density (OD) at 450 nm
was measured within 15 min.