Patent ID: 7939283

Claim:
A set of articles for binding an analyte in a mixture to form a cross-linked assembly, formation of said assembly effecting a detectable increase in mixture turbidity compared to a mixture of said articles in the absence of said analyte, each article in said set of articles being unattached to any immobile solid surface, said set of articles comprising: a) a first analyte-binding substance that specifically binds said analyte, said first analyte-binding substance being attached to a first particle either directly or via a linker, said first particle also being attached to a first member of a specific binding pair; b) a second particle attached to a second member of said specific binding pair; c) a second analyte-binding substance that specifically binds said analyte, said second analyte-binding substance being attached to a third particle directly or via a linker; said first analyte-binding substance and said second analyte-binding substance being capable of binding a single analyte molecule simultaneously.