Abstract:
An apparatus for judging an agglutination has a transparent plate stand 5 for supporting a microplate 7 and perforated with positioning openings 9 for centering of each well 8 of the microplate. A light source and TV camera 12 are disposed above the microplate, an image memory 13 stores the output of the camera, a processor 15 differentiates the stored image to determine its profile, and the picture elements of the differentiated image having intensity levels larger than zero are counted. A calculator 17 produces coefficients of variation, which are plotted against the image profile and compared with a reference value to remove contrast irregularities.
Abstract:
The disclosed methods improve conventional agglutination processes for assaying immunoreactive and like substances, primarily by improving the measurement of the agglutination itself. Suspensions containing agglutinated particles are automatically inspected, preferably intermittently during the agglutinating reaction, and the resulting data are processed to identify individual particle aggregates of a selected limited class, which may, for example, comprise aggregates having sizes within a limited size interval. The numbers of such aggregates are compared with corresponding reference values obtained with standard solutions and suitable controls to evaluate the concentration of one of the reactive substances, or other information. The aggregate size intervals and other parameters which are used to define aggregate classes are preferably selected with attention to the detailed behavior of each test system.