Assays using reference microparticles

An assay for determining the presence of at least two analytes in a sample, comprising the steps of:

• (a) mixing the sample and predetermined amounts of first test microparticles having disposed thereon a binding molecule which bind a first analyte, second test microparticles having disposed thereon a binding molecule which binds a second analyte, and reference microparticles non-reactable with the first and second analytes and the first and second binding molecules, to form a reaction mixture and allow for the first binding molecule to bind the first analyte and the second binding molecule to bind to the second analyte;
• (b) counting the numbers of the non-reacted first test microparticles, the non-reacted second test microparticles, and the reference microparticles optically or electronically;
• and
• (c) comparing the number of non-reacted first test microparticles to the reference microparticles to thereby establish a first test value, and comparing the number of non-reacted second test microparticles to the reference microparticles to thereby establish a second test value, so that the presence of the first and second analytes in the sample may be determined.

An assay for determining the presence of an analyte in a sample, comprising the steps of:

• (a) mixing the sample and predetermined amounts of test microparticles having disposed thereon a binding molecule which binds the analyte, and reference microparticles non-reactable with the analyte and the binding molecule, to form a reaction mixture and allow for the binding molecule to bind the analyte;
• (b) counting the numbers of the non-reacted test microparticles and the reference microparticles;
• and
• (c) comparing the number of non-reacted test microparticles to the reference microparticles to thereby establish a test value so that the presence of the analyte in the sample may be determined.

An assay for determining the presence of at least two analytes in a sample, comprising the steps of:

• (a) mixing the sample and predetermined amounts of first test microparticles having disposed thereon a binding molecule which bind a first analyte, second test microparticles having disposed thereon a binding molecule which binds a second analyte, and reference microparticles non-reactable with the first and second analytes and the first and second binding molecules, to form a reaction mixture and allow for the first binding molecule to bind the first analyte and the second binding molecule to bind to the second analyte;
• (b) counting the numbers of the non-reacted first test microparticles, the non-reacted second test microparticles, and the reference microparticles;
• and
• (c) comparing the number of non-reacted first test microparticles to the reference microparticles to thereby establish a first test value, and comparing the number of non-reacted second test microparticles to the reference microparticles to thereby establish a second test value, so that the presence of the first and second analytes in the sample may be determined.