Agglutination method for the determination of multiple ligands

A method for determining the presence or absence of each of a predetermined number of different ligands selected from one or two ligands in a liquid, semi-liquid or pasty specimen, by a direct or indirect agglutination, or an agglutination inhibition method by competition, comprising the steps:

• contacting the specimen with a predetermined number of homogeneous populations of fluorescent beads, each population having a specific fluorescence and having one or more predetermined antiligands fixed to their surface, said predetermined number of populations being equal to said predetermined number of ligands;
• analyzing said specimen containing said beads using a measuring means capable of discriminating between the specific fluorescence of said beads for each ligand, said measuring means being selected from the group consisting of a flow cytometer, an image analyzer and a laser sweep system;
• determining in response to said analyzing step the number of non-agglutinated beads, the number of agglutinated beads, the number of bead aggregates and for each aggregate, the number of the beads it comprises, by absolute measurement of the intensity and the fluorescence wavelength of each particle or aggregate of particles, one by one;
• and
• correlating the information determined in said determining step with the presence or absence in said specimen, of each of said different ligands to thereby enable the simultaneous determination of a plurality of ligands using a single bead contacting step.