Figure 6: Microscopic views of Heinz bodies after mild heating of blood samples obtained from one healthy donor, redrawn from Sugawara et al. [32]. Using a temperature-untreated sample as a control, aliquots of freshly drawn venous blood were subjected to mild heating at 37°C, 40°C, 42°C, 45°C and 48°C for 30 min. Heinz bodies were then visualized by exposure to acetylphenylhydrazine and dyeing with crystal violet. The changes that occurred within erythrocytes were observed by light microscopy under oil immersion.