Abstract: Provided herein is a method of detecting a level of cell injury in a subject, the method comprising detecting an amount of extracellular telomeres in a biological sample from the subject. The amount of extracellular telomeres as compared to a control amount indicates the level of cell injury in the subject. Further provided is a kit for detecting a level of apoptosis in a subject, the kit comprises first and second nucleic acid sequences, wherein the first and second nucleic acid sequences hybridize with an extracellular telomere; and a container. The first and second nucleic acid sequences can comprise SEQ ID NO: 1 and SEQ ID NO:2.