Scanning electron microscopy of normal and pathological human erythrocytes.

Abstract

A few drops of human blood were fixed in a relatively large volume of glutaraldehyde of various concentrations. After dehydration in acetone the blood cells were dried on glass slides in a warm breeze, coated with carbon and gold and observed under the scanning electron microscope.1. The deformations of erythrocytes caused by the osmotic effect of the fixative were examined. Large differences in osmotic resistance were shown among individual cells especially in hypotonic fixation. Glutaraldehyde concentration of 1% (in a 0.1M phosphate buffer) was found to be optimal for the preservation of the natural shape of normal erythrocytes.2. After this fixation the normal erythrocytes were represented by smooth-surfaced biconcave disks occasionally mingled with uniconcave ones. Some erythrocytes showed one or several wart-like elevations in their cell surface. These are believed to correspond to the segresome-like appendage seen in the transmission electron microscopy of sectioned erythrocytes (MIYOSHI and MATSUKURA, 1969).3. As pathological materials, the erythrocytes in elliptocytosis, hereditary spherocytosis and aplastic anemia were observed and their morphological abnormalities were described. Small conic pits were found on the surface of the erythrocytes in spherocytosis.