2.3 Enzyme-linked immunosorbent assay (ELISA) for CN component specific IgE levels
The αs1-, β-, and κ-CN-specific IgE levels were evaluated by indirect ELISA.4 The relative immunoglobulin levels (%) for each sample were calculated based on the reference serum with high αs1-CN-specific immunoglobulin levels. These measured values were used in this study.