1 - 3 hours
||Rat Rattus norvegicus
||Gavrieli Y, Sherman Y, Ben-Sasson SA. Identification of programmed cell death in situ via specific labeling of nuclear DNA fragmentation. J Cell Biol. 1992 Nov119(3):493-501. abstract, p.499 right column bottom paragraph & p.500 left column top paragraphPubMed ID1400587
||P.493 right column 3rd paragraph:"In this work [investigators] describe the development of a method for an in situ labeling of DNA breaks in nuclei, in tissue sections processed through the routine procedure of histopathology,
and its utilization for the study of tissue dynamics. The method is based on the specific binding of terminal
deoxynucleotidyl transferase (TdT) to T-OH ends of DNA, ensuing a synthesis of a polydeoxynucleotide polymer. After
the exposure of nuclear DNA on histological sections by proteolytic treatment, TdT was used to incorporate biotinylated deoxyuridine at sites of DNA breaks. The signal was amplified
by avidin-peroxidase, enabling conventional histochemical identification by light microscopy. The method of TdT-mediated dUTP-biotin nick end labeling (TUNEL) was tested on a variety of tissues in which the
migration of cells to their final destination is already delineated unequivocally or in tissues that are known for their active PCD [Programmed cell death]."
||Abstract:"A detailed analysis revealed that the process is initiated at the nuclear periphery, it is relatively short (1-3 h from initiation to cell elimination) and that PCD appears in tissues in clusters." P.499 right column bottom paragraph:"[Investigators'] estimate ranges between 1 to 3 h and is based on the rate of accumulation and time of plateau
of PCD in the thymocytes in vitro (Fig. 5)." P.500 left column top paragraph:"This estimated 1-3-h time
flame is in agreement with Kerr et al. (1987), who suggested a duration of only a few hours for the PCD process. In other words, the occurrence of PCD in slow renewing tissues should be a very rare event and even in tissues with a high turnover rate the identification of cells undergoing PCD
could be compared with the probability of capturing cells in mitosis. Nevertheless, the transient nature of PCD should not obscure its importance."