| abstract |
An improved indirect assay and article for determining an antigen in a liquid sample. The assay utilizes a piezoelectric oscillator which has been coated with the antigen or a protein mixture containing the antigen being determined. The antigen-coated oscillator is contacted with the liquid sample and a predetermined amount of an antibody specific for the antigen being determined. The amount of free antigen in the sample, if any, can be determined by measuring the change in frequency of the oscillator following contact with the liquid sample and the antibody, and referring to a standard curve. |