Patent ID: 7563584

Claim:
A method of detecting the activation state of at least a first and a second activatable protein in single cells, said method comprising the steps of: a) providing a population of cells comprising said first and said second activatable proteins, wherein said first and second activatable proteins are distinct proteins that each have at least an activated isoform, and a non-activated isoform; b) permeabilizing said population of cells; c) contacting said permeabilized population of cells with at least two distinguishably labeled activation state-specific antibodies, wherein a first of said at least two distinguishably labeled activation state-specific antibodies is specific for said activated isoform of said first activatable protein; and a second of said at least two distinguishably labeled activation state-specific antibodies is specific for said activated isoform of said second activatable protein; and d) using flow cytometry to detect binding of said first and said second distinguishably labeled activation state-specific antibodies to their corresponding activated isoform of said first and second activatable proteins in single cells of said population of cells, wherein said binding of said first distinguishably labeled activation state-specific antibody is indicative of the activation state of said first activatable protein, and said binding of said second distinguishably labeled activation state-specific antibody is indicative of the activation state of said second activatable protein.