DBA colonies are smaller than normal at low or high erythropoietin concentrations. Mononuclear cells were cultured in liquid in phase I without erythropoietin, and in semisolid clonogenic culture in phase II. While the numbers of colonies from DBA patients were the same as from normal individuals, the DBA colonies were much smaller, since they contained fewer cells. See the complete figure in the article beginning on page .
