POSTMORTEM CHANGES OF OSMOTIC FRAGILITY AND RED CELL SHAPE
The osmotic fragility and morphological changes of red cells in rat corpses were investigated in order to estimate the postmortem interval. The osmotic fragility was measured by a coil planet centrifuge (CPC) system. Soon after death, hemolysis starting point (HSP)and hemolysis end point (HEP) were shown to shift to higher osmotic pressure and the shift of HSP was observed up to 12 hours postmortem. On the contrary, HEP became fairly constant thereafter and resulted in the change of hemolysis pattern from monophase to flat. The changes of osmotic fragility especially at HSP well correlated with the morphological changes obtained by the scanning electron microscopy. From these results, it was shown that the shift of HSP together with the analysis of hemolysis pattern obtained by CPC system was very useful to estimate the early postmortem interval.