Disk-Sphere Transformation in Mammalian Red Cells

The transformation of red cells from disks to spheres in a drop of a saline suspension between slide and coverglass (Ponder, 1929, 1934) has recently been shown by one of us (Furchgott, 1939) to be the result of two changes. The first is a rise in the pH of the suspension above 9·2 because of the alkaline nature of the glass surfaces. The second is an adsorption out of the suspension by the glass surfaces of a substance which, if present, prevents the formation of spheres at the pH attained between slide and coverglass. The determination of the chemical nature of this substance, termed the “anti-sphering factor”, and experimental attempts to gain an insight into the physical mechanism of the phenomena of shape changes are the subject of this paper.