Abstract: A high-throughput method for identifying a compound or biomolecule that modulates cell senescence involves simultaneously measuring in a cell population exposed to the test compound or biomolecule, the expression of a senescence marker and cell number, wherein each well contains a single test compound; and determining from said simultaneous measurements whether the test compound increases or decreases cell senescence. In various embodiments, the method is useful is identifying compounds that delay the aging process of normal healthy cells, or identifying a compound useful as a tumor suppressor or identifying a compound useful in the treatment of cancer.