The invention provides a method capable of determining the presence or absence of each of a plurality of different ligands in a specimen. The specimen is contacted with a predetermined number of different homogeneous populations of fluorescence beads having one or more predetermined antiligands affixed...http://www.google.com/patents/US5405784?utm_source=gb-gplus-sharePatent US5405784 - Agglutination method for the determination of multiple ligands
