An Enzyme-Linked Immunosorbent Assay (Elisa) for Measurement of Human Igg Subclass Levels in Serum

Abstract

We established an enzyme-linked immunosorbent assay (ELISA) to quantify human IgG subclasses in serum. IgG subclasses captured with subclass-specific mouse MoAbs could be detected with enzyme-labeled goat anti-human IgG. We screened the MoAbs which were suitable for the method from the commercially available MoAbs raised against human IgG subclasses. The specificity of the present ELISA for each subclass was clarified by the experiments as follows: (a) identification of individual IgG subclasses purified from total IgG by protein A column chromatography and (b) identification of a certain specific subclass which increased relatively in monoclonal (M)-proteinemia-patient sera compared with normal. We could detect each subclass with the sensitivity of 4.0 ng/ml for IgG₁, 13 ng/ml for IgG₂, 0.5 ng/ml for IgG₃ and 0.4 ng/ml for IgG₄ using pooled normal serum calibrated against a reference serum 67/86 from the World Health Organization (WHO) as a standard.

Key Words:

• Human
• IgG subclass
• Enzyme Immunoassay