Abstract
The study of whole negatively stained cells has revealed details of cellular organelles in rat venous endothelial cells. In particular, details of surface membrane organelles and small tubular structures were demonstrated. The surface membrane organelles which appeared "vesicular-like" were found to be connected with small tubular attachments. These findings were correlated with those described by other techniques. It is significant that this simple technique appears to permit the demonstration of fine details of three-dimensional cytoplasmic structures.