Contrast-enhancement for the image of human immunodeficiency virus from ultrathin section by immuno electron microscopy

A simple contrast-enhancement method is described for electron microscopic imaging of the human immunodeficiency virus (HIV) from a sample embedded in Lowicryl K4M resin: by immuneelectron microscopy. Ultrathin sections were treated with a mixture of ruthenium red dye (RR) and osmium tetroxide (OsO4). This treatment provided good contrast enhancement of the entire ultrastructural image of virus particles without the loss of immunolabelling. RR/OsO4 solution is simple to prepare and provides a better contrast than that which is achieved during conventional post-embedding immunoelectron microscopy. Treatment of ultrathin sections from low tempera ture-embedded samples with RR/OsO4 solution is recommended. (C) 1998 Elsevier Science B.V. All rights reserved.