Analysis of iron content in individual human red blood cells by electron microprobe and scanning electron microscope

Abstract

The iron content of single human red blood cells has been assessed using electron microprobe analysis and scanning electron microscope. Cells for microanalysis consist of a fixed-washed and freeze-dried preparation. This preparative procedure improves stability and spatial resolution of the analytic method. The reference standard employs compressed pellets of purified iron-containing human hemoglobin and human albumin, respectively. The cell preparation and reference standard remain stable for long periods of time. Differences in Fe content and its distribution among individual red cells from both normal subjects and sickle cell anaemia patients have been measured by the quantitative and semi-quantitative techniques (wavelength and energy dispersive X-ray spectrometry). There are several points which can be made from this study. One concerns the estimate of iron on a cell by cell basis, the average variation among cells being slightly over 13% ranging from 6% to 19.4% by individuals (samples) or from 11% to 14% by ethnic groups. These differences are thus closely comparable across ethnic grouping with a possibility of high level in Asians and lower level in sickle cell anaemia patients.