Techniques for the Study of Apoptosis in Bone

AbstractOver the past five years there has been an explosion of interest in the process of apoptotic cell death. The fact that, in contrast to necrotic death, apoptosis constitutes a precisely regulated, energy-dependent form of death has led to interest in the potential to control this death process through an understanding of the molecular mechanisms involved in its initiation and occurrence. Early descriptions of apoptosis were based on morphological changes in cells (cell shrinkage, condensation and margination of chromatin nuclear fragmentation, and production of membrane-bound apoptotic bodies), and despite the more recent identification of a number of biochemical (e.g., ordered DNA fragmentation and activation of a range of caspase enzymes) and ultrastructural phenomena (e.g., externalization of phosphatidylserine molecules at the plasma membrane) specific to apoptosis, the morphological criteria are still often regarded as the "gold standard" (1). Unfortunately, the use of morphological criteria to assess the apoptotic state in many cell types involves the use of high magnification microscopy (often electron microscopy), which precludes studying the high numbers of individual cells necessary for an assessment of apoptosis at a tissue level. We have attempted to address these difficulties by identifying more than one apoptotic characteristic at relatively low magnifications. Hence we assess (1) DNA fragmentation in situ, (2) cell loss, and (3) identification of internucleosomal sized increments of DNA, produced during DNA destruction (DNA ladders).KeywordsExpiration DateNick TranslationSodium PerchlorateToluidine Blue StainingNecrotic DeathThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.