fresh cell 7.27±0.52: fixed embedded cell 7.37±0.30 µm
||Human Homo sapiens
||Silverman L, Glick D. Measurement of protein concentration by quantitative electron microscopy. J Cell Biol. 1969 Mar40(3):773-8. p.776 left column top paragraphPubMed ID5765765
||Abstract: "The method of quantitative electron microscopy was applied to the measurement of protein concentration in thin sections. The human erythrocyte was selected as a model because of its apparently uniform protein concentration. Phosphotungstic acid (PTA) in aqueous solution was used as a reversible stain for protein, and PTA-stained Dowex resin spheres were embedded along with the red cells as standards for measurement of section thickness. The mass of stain removed from a given area of sectioned red cell by buffer (pH 7.4) was measured by quantitative electron microscopy. From the stoichiometry of the reaction between PTA and red cell protein established in this study, the amount of protein present in the measured area was calculated."
||P.776 right column 2nd paragraph: "Change in Red Cell Volume after Embedding: The red cells appeared to retain their shape as biconcave discs quite well, although some sickling was evident (Figs. 1, 2). The average diameter and sd of the fresh cells was 7.27±0.52µm, and that of the fixed embedded cells 7.37±0.30 µm. From the ratio of the diameters cubed, the volume of embedded to unembedded cells was calculated to be 1.04. After correction for volume change during embedding, the hemoglobin concentration was calculated to be 33.8 g per 100 ml of packed cells."