Effects of prefixation and fixation times on apoptosis detection by in situ end-labeling of fragmented DNA.

摘要: Objective Apoptosis is considered to play an important role in the pathogenesis and progression of neoplasia. An situ 3'-end DNA labeling (TUNEL) method was recently developed has been widely used identify apoptotic cells tissue sections. However, sometimes TUNEL labels many more than expected. We investigated effects prefixation time fixation on index detected by this method. Materials methods Using spleen thymus rats, (0, 1, 2, 4, 6, 12, 24, 48, 72 hours) at 4 degrees C (6, 72, 96 hours; 3 weeks) were examined Agarose gel electrophoresis extracted from specimens each also performed. Results In comparison with control (no time), which showed scattered positive distinct staining restricted nucleus, splenic unfixed for 2 hours or thymic cytoplasmic cells. Moreover, as prolonged, number gradually increased. analysis sections left longer 24 a ladder pattern consisting multiples about 200 base pairs. Conclusions Two limit precise identification apoptosis The false-positive intervals may have due internucleosomal cleavage following necrosis. contrast, length buffered formalin seemed no effect results obtained