The frequency of bone marrow cells that bind erythropoietin

The frequencies of rat and mouse bone marrow cells capable of binding erythropoietin were studied by both direct fluorescence and indirect immunofluorescence. We found that between 1-2% of the cells bound erythropoietin, that the binding was specific, and that the number of cells that bound erythropoietin was, in part, a function of the erythropoietic state of the donor animal. A statistical method for evaluating the data obtained is included.