Abstract: Objective To investigate the relationship between postmortem interval (PMI) and the metabolic law of the amount of DNA in cells. Methods After different PMI from the heart, liver, spleen and kidney were taken into pieces respectively, then centrifuged and digested to get suspending cells fluid. The amount of DNA of rats′viscera were detected by flow cytometry after stained by fluorescence , and also inspect the amount of DNA in different periods to find out the law of its variation. Results It showed a descendent trend of the amount of DNA in cells after different PMI, especially in spleen. Conclusion The amount of DNA of all the viscera grows downwards after death, this might be applyed in forensic estimation of PMI.

Key words: postmortem interval, DNA degrade, flow cytometry