TOTAL MASS AND IRON CONTENT DETERMINATION OF HEMOSIDERIN GRANULES BY QUANTITATIVE ELECTRON MICROSCOPY

The total mass and iron content of in vitro prepared hemosiderin granules have been determined by quantitative electron microscopy. Good agreement has been obtained between the measured values and the values calculated for spherical particles of hemosiderin composed of closely packed molecules of ferritin. The results can be used to evaluate the iron bound to hemosiderin in single cells. It appears that in some diseases, like thalassemia, erythropoietic cells contain more iron than is actually needed for hemoglobin synthesis, suggesting the existence, in these cells, of a competition between ferritin and hemoglobin for free iron. (Author) Pub. in Journal of Ultrastructure Research, v13 p85-91 1965. (Copies available only to DDC users).