Quantitative morphological analysis of erythrocytes by reflection contrast microscopy.

In reflection contrast erythrocytes show characteristic interference lines consisting of alternating maxima and minima. The distance between neighboring interference lines corresponds to a difference in cell thickness of about 113 nm. Some visual and graphic methods for quantitative morphological analysis are described; their application is demonstrated using unstained and stained blood smears of normal individuals and patients with hereditary spherocytosis, sickle cell anemia, and thalassemia.