Patent ID: 8206939

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) contacting a population of cells comprising a first activatable protein having a first and second isoform and a second activatable protein having a first and second isoform with a plurality of activation state-specific binding elements, wherein said plurality of activation state-specific binding elements comprise: i) a first activation state-specific binding element that binds to said first isoform of said first activatable protein; and ii) a second activation state-specific binding element that binds to said first isoform of said second activatable protein; wherein said first activation state-specific binding element and said second activation state-specific binding element are distinguishably detectable, and b) detecting the presence or absence of binding of said first and second binding elements in single cells in said population of cells to determine the activation state of said first and said second activatable proteins in said single cells.