| abstract |
A method and article for the determination of a particular subclass of antibody, e.g., IgA, IgE, IgM, etc., are disclosed. The method utilizes a piezoelectric oscillator having bound to the surface thereof an antigen specific for the antibody being determined. The antigen-coated oscillator is exposed to a solution containing an unknown amount of the antibody. After the antibody in the solution has attached to the antigen on the oscillator, the oscillator is exposed to a substance (sandwiching substance) which selectively binds to a specific subclass of the antibody being determined. The frequency of the oscillator is measured before and after exposure to the sandwiching substance. The change in frequency is related to the amount of the subclass of antibody bound to the oscillator, and the amount of the subclass of antibody in the solution can be quantified by reference to a standard curve. |