The morphology of redox-dye-treated HbH-containing red cells: differences between cells treated with brilliant cresyl blue, methylene blue and new methylene blue.

The ultrastructure of redox-dye-treated HbH-containing red cells has been shown to be dependent on the nature of the redox dye used. Brilliant cresyl blue causes the formation of a large number of small inclusions which are invariably attached to the inner surface of the red cell membrane. Methylene blue and new methylene blue cause the formation of a much smaller number of larger inclusions only some of which appear to be membrane-bound. These ultrastructural differences are reflected in marked differences in the light microscope appearances of the supravitally-stained cells.