Immunoassay by light scattering intensity anisotropy measurements

摘要

Method and apparatus for determining the concentration of any of a wide range of antigen or antibody molecules with a high degree of specificity, accuracy and sensitivity. Antigen or antibody concentration is determined by effecting an agglutination reaction between carrier particles in a liquid medium, exposing the liquid medium to a beam of light, and measuring the ratio of the intensities of light scattered at two different angles as a function of antigen or antibody concentration. The unknown concentration of antibody or antigen is determined by comparison with similar measurements of the anisotropy ratio using known concentrations of the molecule being tested for. The agglutination reaction is performed using carrier particles coated with an agglutinant. The carrier particles should be fairly uniform in size and their diameter can be less than or comparable to the wavelength of light. By this invention, one may specifically ascertain the absolute concentration of the antigen or antibody in question in the sample being analyzed. In addition to detecting antigen or antibody molecules, the process of this invention can be used to determine the concentration of any substance capable of specifically promoting or inhibiting an agglutination reaction.