The FITC-labelled anti-human IgG immunoassay and its work curve in this system. (a) Spectra of human IgG in series concentration in the reactions. From curves 1 to 7 the human IgG concentration was 0 ng/mL, 30 ng/mL, 50 ng/mL, 100 ng/mL, 0.2 μg/mL, 0.4 μg/mL, 0.5 μg/mL, 1.0 μg/mL, 1.5 μg/mL, 2.0 μg/mL, and 3.0 μg/mL. (b) The correlation of fluorescent intensity and concentration of human IgG. The data were repeated for 3 times.