Patent ID: 7851229

Claim:
A method of measuring at least one analyte in a sample, comprising the steps of: incubating a mixture in a container, said mixture comprising a buffer, solid particles, said sample, and an affinity agent operable to bind the at least one analyte to said particles, and establishing a fully suspended phase where said particles are substantially uniformly distributed throughout said buffer; gravitationally separating said incubated fully suspended phase in said container to give a particle-rich phase; initially measuring a parameter of said at least one analyte in said fully suspended phase substantially at the beginning of the separating step, and subsequently measuring a parameter of said at least one analyte in said particle-rich phase at the end of the separating step, said initial and subsequent measuring steps each comprising directing electromagnetic radiation through said container; and using said measurement parameters to calculate the proportional distribution of said at least one analyte in said fully suspended phase and in said particle-rich phase.