The Journal of Membrane Biology

, Volume 245, Issue 4, pp 185-190

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

Changes in Surface-Charge Density of Blood Cells After Sudden Unexpected Death

  • Joanna KotyńskaAffiliated withInstitute of Chemistry, University of Bialystok
  • , Aneta D. PetelskaAffiliated withInstitute of Chemistry, University of Bialystok Email author 
  • , Michał SzeremetaAffiliated withDepartment of Forensic Medicine, Medical University of Bialystok
  • , Anna Niemcunowicz-JanicaAffiliated withDepartment of Forensic Medicine, Medical University of Bialystok
  • , Zbigniew A. FigaszewskiAffiliated withInstitute of Chemistry, University of BialystokLaboratory of Electrochemical Power Sources, Faculty of Chemistry, University of Warsaw


The objective of the investigation was evaluation of postmortem changes of electric charge of human erythrocyte and thrombocyte membranes after sudden unexpected death. The surface charge density values were determined on the basis of the electrophoretic mobility measurements of the cells carried out at various pHs of electrolyte solution. The interactions between both erythrocyte and thrombocyte membranes and electrolyte ions were studied. Values of parameters characterizing the membrane—that is, the total surface concentrations of both acidic and basic groups and their association constants with solution ions—were calculated on the basis of a four-equilibria mathematical model. The model was validated by comparison of these values to experimental data. We established that examined electric properties of the cell membranes are affected by sudden unexpected death. Postmortem processes occurring in the cell membranes can lead to disorders of existing equilibria, which in turn result in changes in values of all the above-mentioned parameters.


Erythrocytes Microelectrophoresis pH measurement Sudden unexpected death Surface charge density Thrombocytes