Multiplex assay methods and compositions

A composition, comprising:

• a first solid-phase support comprising a first specific binding agent and a photosensitizer, the photosensitizer light excitable to activate oxygen to produce singlet oxygen;
• a second solid-phase support comprising a second specific binding agent and a first emission system comprising an energy acceptor activated by singlet oxygen, the first emission system activated by singlet oxygen to emit a first light signal characterized by a first emission spectrum;
• and
• a third solid-phase support comprising a third specific binding agent and a second emission system comprising an energy acceptor activated by singlet oxygen, the second emission system activated by singlet oxygen to emit a second light signal characterized by a second emission spectrum, wherein the first light signal and second light signal are distinguishable.

An assay method, comprising:

• A) providing an assay mixture, comprising, in combination:
• a first solid-phase support comprising a photosensitizer, the photosensitizer light excitable to activate oxygen to produce singlet oxygen, the first solid-phase support further comprising a first member of a selective binding pair selected from the group consisting of:
• enzyme/known or putative enzyme substrate;
• receptor/known or putative ligand;
• antibody/antigen;
• and nucleic acid/complementary nucleic acid,
• a second solid-phase support comprising a second specific binding agent and a first emission system comprising a first energy acceptor activated by singlet oxygen, the first emission system activated by singlet oxygen to emit a first light signal characterized by a first emission spectrum, the second solid-phase support further comprising a second member of the selective binding pair selected from the group consisting of:
• enzyme/enzyme substrate;
• receptor/ligand;
• antibody/antigen;
• and nucleic acid/complementary nucleic acid, and
• a third solid-phase support comprising a third specific binding agent and a second emission system comprising a second energy acceptor activated by singlet oxygen, the second emission system activated by singlet oxygen to emit a second light signal characterized by a second emission spectrum, wherein the first light signal and second light signal are distinguishable, wherein the specific binding agent selectively binds to a modification of the first or second member of the selective binding pair;
• B) irradiating the assay mixture with a light source, activating the photosensitizer to produce singlet oxygen;
• and
• C) detecting the first light signal and the second light signal, wherein detecting the first light signal is indicative of binding of the first member of the selective binding pair with the second member of the selective binding pair and wherein detecting the second light signal is indicative of selective binding of the specific binding agent to a modification of the first or second member of the selective binding pair.

An assay method, comprising:

• A) providing an assay mixture, comprising, in combination:
• a cell having a cell membrane, the cell comprising a first specific binding agent and a photosensitizer associated with the cell membrane, the photosensitizer light excitable to activate oxygen to produce singlet oxygen,
• a first solid-phase support comprising a second specific binding agent and a first emission system comprising a first energy acceptor activated by singlet oxygen, the first emission system activated by singlet oxygen to emit a first light signal characterized by a first emission spectrum;
• B) irradiating the assay mixture with a light source, activating the photosensitizer to produce singlet oxygen;
• and
• C) detecting the first light signal, wherein detecting the first light signal is indicative of proximity of a first target bound to the first specific binding agent and a second target bound to the second specific binding agent.