Improved methods for analysis of apoptosis by flow cytometry

In cells undergoing apoptosis, the characteristic "ladder" pattern of DNA fragments is observed on agarose gel electrophoresis. Such a pattern of DNA degradation generally serves as a criterion for the apoptosis. However, on agarose gel electrophoresis it is difficult to accurately quantify DNA fragmentation. Therefore, quantification of DNA fragmentation is determined by flow cytometry, DNA fragmentation assay etc. In this paper we improved the methods for the analysis of apoptosis by flow cytometry. As a result, we can obtain much information (quantification of apoptosis and cell cycle analysis etc.) from a single sample (1～3×10 6 cells) with the improved methods. The sample is treated with phosphate-citrate buffer. These methods are very simple and convenient