Problems in measurement of erythrocyte calcium

As calcium has increasingly been the object of study in erythrocyte physiology, we reviewed the current methodologies for determination of calcium by atomic absorption spectrometry. The published normal values for erythrocyte calcium vary from 5 to 500 mumol/liter of packed cells. A method based on Harrison and Long's determination of calcium is presented and shows normal red cell calcium concentration to be 0.0149 +/- 0.0023 mumol/ml of packed red cells. The influence of temperature and type of crucible used in ashing red cells is assessed. The method of additions is employed to corroborate our results.