Document 0466
 DOCN  M9490466
 TI    A morphological and immunolabelling study of freeze-substituted human
       and simian immunodeficiency viruses.
 DT    9411
 AU    Grief C; Nermut MV; Hockley DJ; Electron Microscopy and Photography
       Section, National Institute; for Biological Standards and Control,
       Potters Bar, Herts, U.K.
 SO    Micron. 1994;25(2):119-28. Unique Identifier : AIDSLINE MED/94332554
 AB    Rapid freezing, freeze substitution and low temperature embedding were
       used to obtain resin-embedded specimens of HIV and SIV for morphological
       and immunolabelling studies, with particular emphasis on the 'lateral
       bodies' and p6 protein. HIV- or SIV-infected cells were fixed in 3%
       paraformaldehyde and cryoprotected with 0.5 M sucrose. Cells were
       applied to pieces of Whatman No 1 filter paper and impact-frozen onto a
       liquid nitrogen cooled copper block. Specimens were freeze-substituted
       at -90 degrees C using one of three different media: (a) absolute
       methanol, (b) methanol containing 0.5% uranyl acetate, and (c) methanol
       containing glutaraldehyde, osmium tetroxide and uranyl acetate.
       Specimens substituted in methanol and uranyl acetate showed both good
       structural preservation and retention of antigenicity. We found that the
       use of filter paper for supporting the specimen was an important factor
       in obtaining good freezing rates and was more practical than freezing
       mixtures of cells and gelatin. When compared with specimens prepared by
       conventional fixation and embedding, freeze-substituted virus particles
       showed a greater uniformity of shape and size and were more dense in
       appearance. Distinct 'lateral bodies' were not observed in
       freeze-substituted viruses. The viral protein p6 was widely distributed
       in the centre of mature virus particles.
 DE    Animal  Antibodies, Monoclonal  Comparative Study  Freeze
       Substitution/*METHODS  Human  HIV/CHEMISTRY/*ULTRASTRUCTURE
       Immunohistochemistry  Microscopy, Electron
       SIV/CHEMISTRY/*ULTRASTRUCTURE  Tissue Embedding/METHODS  Viral
       Proteins/ANALYSIS  JOURNAL ARTICLE

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