Negatively Stained Lipoprotein Membranes: the Validity of the Image

Abstract

THE use of negative staining techniques in electron microscopy has recently been extended to the examination of lipoprotein membranes^1–3. In view of present attempts to interpret data obtained by these techniques in terms of the molecular organization of the intact, hydrated membrane, attention must be directed to X-ray diffraction data which indicate that the dehydration of such lipoprotein systems generally leads to extensive reorganization of lipid and protein components. Freshly isolated preparations of red cell ghosts, mitochondria, and microsomes (unpublished results) do not give any low angle diffraction bands but the dried preparations all show a strong diffraction at about 60 Å, which is suggested to be characteristic of an independent lipid phase.