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9088816 
Journal Article 
Ultrathin formvar support films for transmission electron microscopy 
Davison, E; Colquhoun, W 
1985 
Journal of Electron Microscopy Technique
ISSN: 0741-0581
EISSN: 1553-0817 
WILEY-LISS 
NEW YORK 
2 
1 
35-43 
English 
WOS:A1985AAF6700005 
We have found that ultrathin Formvar films are easily and reliably made at an air‐water interface by the drop method. By varying the concentration of Formvar in the drop, films of different characteristics can be obtained. Concentrations of 0.25–0.4% in ethylene dichloride produce extremely flat, ultrathin, and stable films that are especially suited for shadowed and negatively stained preparations. Low concentrations (⩽ 0.1%) produce nets consisting of many tiny holes which, after carbon stabilization, are ideal for supporting high‐resolution samples. Above 0.5%, films made by the drop method develop bubbles, and this bubble defect makes them unsuitable for section support. For section support, Formvar films made by the stripping method off mica are far superior to those made off glass. The films are more uniform in surface contour and thickness. They are less readily attacked by alcohols. Consequently, they are more resistant to staining procedures involving organic solvents and continue to be strong and uniform for section support. Copyright © 1985 Wiley‐Liss, Inc. 
Electron microscopy; Formvar; Smoothness; Stability; Support films; Thickness