The Application of Freeze-Cleaving Technics to Studies on Red Blood Cell Fine Structure

A simplified freeze-cleave and replication method of tissue preparation for examination in the electron microscope is applied to studies on red blood cell fine structure. With this technic, the cytoplasm of red blood cells appears to have a uniform pattern of packed granularity, with individual particles approximating the dimensions anticipated for replicas of individual hemoglobin molecules. The cell surface is smooth and partially covered with small particles which may represent antigens, enzymes, or some structural proteins. The possibility that particles seen in cells and on cell membranes may represent an artifact is discussed. Pretreatment of cells prior to freezing influences the plane of cleavage through packed cells so that the plane of cleavage can be preferentially directed either through the cytoplasm or along red cell membranes. The freeze-cleave technic may be of particular value in applications where extensive areas of membrane must be surveyed, such as searching for leukemogenic viruses budding through cell membranes.