The effects of saline solutions on red cell shape: a scanning-electron- microscope-based study.

Red cells appear to change shape in response to alterations in their environment both in vitro and in vivo. To investigate the qualitative aspects of this phenomenon, five drops of a venous blood sample were fixed in buffered glutaraldehyde for baseline observations and 0.5 ml of blood added to 4 ml of four different saline solutions. Triplicated 10-drop samples from the suspensions were fixed in the glutaraldehyde solution after 2.5, 5, 10, 20 and 40 min and prepared for scanning electron microscopy. Red cell shape analysis of the resulting micrographs showed that the cells had changed shape, although no two patterns of change were the same.