Detection of Apoptosis by the TUNEL Assay

Apoptosis is the name given to a normal cell process—that of programmed cell death. As the term implies, this is normally a well controlled and highly regulated series of events leading to the elimination of an “unwanted” cell. Without this process, many stages of embryogenesis would not be complete and immune responses would not be terminated (1 ). Failure to initiate apoptosis can induce many disease states, the most well documented being arthritis and cancer. In these conditions, the normal constraints on the life span of a differentiated cell are not present, so the cell is not eliminated (2 ).