Rehydration of Human Red-Cell Ghosts

Abstract

THE thickness of the surface ultra-structure of the dried red-cell ghost, as measured with the electron microscope or with the leptoscope, can be converted into the thickness of the undried surface ultra-structure only if the amount of hydration is known. If one allows for differences in method and for the loss of protein and lipid which may occur during the preparation of ghosts from red cells, there is agreement, to an order of magnitude, among most of the values which have been obtained for the thickness of the dried ultra-structure (200 A., Waugh and Schmitt¹; 150–300 A., Wolpers²; 300–800 A., Bernhard³; 1000 A., Bessis and Bricka⁴; 140–1000 A., Latta⁵), but there are only two estimates of the amount of hydration. These are a hydration of 25 per cent at most (Waugh and Schmitt¹, on the basis of leptoscopic measurements), and a hydration so great that the protein-containing layer of the surface ultra-structure would be about 5000 A. thick and would contain only about 2 per cent protein (Mitchison⁶, on the basis of birefringence measurements). Any additional evidence which bears on the degree of hydration of the ghost is interesting in view of the discrepancy among the existing estimates.