The knowledge of signaling pathways that are triggered by physiological and pathological conditions or drug treatment is essential for the comprehension of the biological events that regulate cellular responses. Recently, novel platforms based on “reverse-phase protein arrays” have proven to be useful in the study of different pathways, but still lack the possibility to detect events in the complexity of a cellular context. We have developed an “Immunocell-array” of cells on chip where, upon cell plating, growing, drug treatment and fixation, by spotting specific antibodies we can detect the localization and state of hundreds of proteins involved in specific signaling pathways. By applying this technology to mammalian cells we have analyzed signaling proteins involved in the response to DNA damage and identified a chromatin remodeling pathway following bleomycin treatment. We propose our technology as a new tool for the array-based multiplexed analysis of signaling pathways in drug-response screening, for the proteomic of profiling patient cells, and ultimately for the high-throughput screening of antibodies for immunofluorescence applications.