Abstract: Apoptosis is cell death defined by some ultrastructural characteristics. DNA agarose gel electrophoresis is suitable for cultured cells consisting of homogeneous cells in which apoptosis is relatively easy to induce using appropriate stimuli, but often fails to detect a typical DNA ladder when tissues consisting of heterogeneous cells are used and contain only a few apoptotic cells. It is known that the terminal deoxynucleotidyl transferase (TdT)−mediated dUTP−biotin nick end−labeling (TUNEL) method detects both apoptotic and necrotic cells, although TUNEL can detect also newly yielded free 3′−OH ends of DNA. Fluorescence dyes specifically bind with DNA, clearly showing fragmented nuclei. Annexin V enables classification of the apoptotic cells into different stages, because it can detect the externalization of phosphatidylserine in the cell membrane which occurs at the early stage of apoptosis. The disadvantage of fluorescence dyes and annexin V is to be applicable only to unfixed materials. Western blot analysis has several advantages such as its applicability to both cells and tissues, and semiquantification of a protein expressed in materials used, but is unsuitable for analysis of the topographic distribution of cells producing apoptosis−related protein such as the caspase family. As mentioned above, most of the apoptosis detection methods focus only on one of the apoptotic characteristics, thereby limiting their application to apoptosis detection. Therefore, it is required to combine several methods for the precise detection of apoptosis.