Abstract: Methods, arrays and kits are provided for rapidly and efficiently identifying and quantifying multiple different activated transcription factors in a biological sample at the same time. In one embodiment, the method includes the step of mixing a library of transcription factor probes with a sample containing activated transcription factors. The transcription factor probes that have bound to the activated transcription factors may be isolated from the complexes formed between the probes and the activated transcription factors. The bound probes can be identified, for example, by using an array of hybridization probes.