Rapid detection of ringed sideroblasts in erythremic myelosis.

When normoblasts from patients with chronic erythremic myelosis were stained with the anthraquinone dye, alizarine red S, a purple perinuclear halo appeared. This halo corresponded in location to siderotic granules stained with a conventional iron stain. The rapidity of the alizarine red S stain makes it potentially useful for the detection of pathological sideroblasts in certain refractory anemias.